50 years on

Sunday 24th May will be the 50th anniversary of the announcement by the British Government that the UK was to “go metric” within 10 years.  However, 50 years later we are still little more than half way there.  Why has it taken so long?  and when will it end?

Why has it taken so long?

The process was bungled from the start.  A low key  announcement to Parliament was made by the President of the Board of Trade, Douglas Jay MP, in response to a private notice question (see this link and scroll to Appendix B for the full text). From this statement it is clear that the issue was seen as primarily a response to the request by British industry to adopt the world system in order to facilitate international trade. No thought appears to have been given to the major cultural implications of the change, to the extension of “metrication” (as it was called) to retailing, road signs, education or the health service.  Serious planning did not begin until the establishment in 1968 of the (advisory) Metrication Board, and little attempt was made to justify the change to the general public – or to counter the predictable hostility from traditionalists, especially (though not exclusively) in the Opposition Conservative Party.

Following their election victory in 1970, the new Conservative government conducted a review of the whole process.  The conversion of road signs (planned for 1975) was cancelled, and the 1972 White Paper insisted that the general changeover should be voluntary, with no question of a co-ordinated target for completion.  However, the teaching of metric measures in science and maths lessons became mandatory in state schools from 1974.

It should be noted that accession to the then European Economic Community in 1973 was largely irrelevant since by then the changeover had already begun , and in any case the UK and Ireland had negotiated derogations allowing them to postpone completion indefinitely except where it concerned cross-border trade.  These derogations have now been made permanent.

Modest progress was made in the later 1970s but the ensuing Labour Government lacked a secure Parliamentary majority, and following the Conservative victory at the 1979 election the Metrication Board was abolished with its work unfinished.  However, during the 1980s more and more goods began to be sold in metric measures (notably petrol), and from 1995 packages were required to be marked in metric units.

Meanwhile, other Commonwealth countries, such as Australia, which had started the metrication process long after the UK, had substantially completed their conversion by 1980.

Increasingly during the 1990s and 2000s metrication came to be identified with “Europe”.  Although the EU had always agreed to derogations requested by successive British governments, attempts to implement UK domestic legislation were invariably portrayed by the media as a “Brussels diktat”, and it was difficult to hold a sensible conversation about the merits of the issue.  Politicians were complicit in this travesty, often blaming Brussels rather than trying to justify their decisions.  Thus, in 2001/2, we had the so-called “metric martyrs” – a public relations disaster for metrication in which the prosecutions of various small shopkeepers and market traders were gleefully portrayed by the tabloid media as Brussels bureaucrats trampling on British values.

Apart from the deletion of the acre from official usage in 2009, there has been no further progress, and it can be said that metrication has ground to a halt.  Even the modest attempt to require dual metric/imperial units on vehicle height and width restriction signs was reversed by the Coalition Government in 2010.

The current muddle

So we have arrived at a situation where many aspects of British life are metric, but many remain imperial – at least on the surface.  Examples are listed below:


  • Most British industry (for internal operations)
  • Public sector (including the armed services, NHS, police and councils)
  • Package labelling
  • Sale of “loose goods” in supermarkets
  • Fuel, energy
  • Building and construction (including road design)
  • Tachographs
  • School teaching of maths and science
  • Building regulations
  • Planning permissions
  • Ordnance Survey maps
  • Met Office
  • Rugby, athletics, swimming


  • Interface between industry, NHS – and the public
  • Many street markets and independent small shops
  • Road signs (distance, speed limits)
  • Tabloid media
  • Estate agents
  • Holiday brochures
  • School teaching outside maths and science
  • Commercial road atlases
  • Commentators on football, cricket, golf
  • “Top Gear”

When will it end?

The official Government view is that metrication is now complete, and that no further measures are planned.  This view is based on the assumption that, as younger, metric-educated people progress through the age cohorts and eventually replace imperial-educated people, metric units will become the default for the whole population.  Thus the problem will solve itself.

A recent survey by YouGov for the UK Metric Association showed that this assumption is false.  Although there are some exceptions, in most fields (such as measuring personal height and weight, food preparation, estimating fuel consumption) little progress has been made since the abolition of the Metrication Board in 1980.  It is clear that the voluntary/gradual approach has failed and will not succeed in the future.    Without specific government action (such as converting road signs) the present “two systems” muddle will continue indefinitely.

So what are the prospects for “specific government action”?  In order to succeed, any such action would need to have the sustained support of the prime minister of the day (since without such support individual ministers can easily be undermined by opponents, including their own civil servants – always assuming they last long enough in the job). Given the unguarded response of David Cameron to a recent interviewer’s question (that he prefers imperial), there is little chance of such support from the current prime minister.

Looking further ahead, who knows?  We can only hope that towards the end of the decade a candidate for party leadership may come forward who is primarily metric-educated, preferably has some understanding of science or engineering, a commitment to ending the current muddle and the management ability and political courage to push it through.  In the meantime it behoves the rest of us to continue making the case for “a single, rational system of measurement”.


29 thoughts on “50 years on”

  1. There is one possible turning point in the near future, namely, the possible independence of Scotland.

    If the Cameron government fails to grant the powers to the Scottish parliament and other bodies that were promised (or even hinted at) during the referendum for independence and if Westminster does hold a referendum on British membership in the EU and England votes heavily to leave and Scotland votes overwhelmingly to stay, then the stage is set for the SNP to call for another vote on independence.

    If that happens and the vote is in favour of independence, then it seems quite possible that an independent Scotland would move to metricate road signs much along the lines of what the Republic of Ireland did not that many years ago (partly to show its independence from Westminster and partly to demonstrate its adhesion to the EU).

    If that happens, what is left of the UK would then have two land borders with countries where the road signs are entirely metric. Perhaps that would be a tipping point for conversion in England, Wales, and Northern Ireland? One can only wonder.


  2. Metrication was doomed from the moment the politicians decided to blame someone else for their inability to make the case for it – even worse than blaming the opposition for the screw up, they blamed “the foreigns” – always guaranteed to bring out the most mulish resistance to anything here in the UK.

    Interesting series of articles on how this arose – typical British stubbornness meets bureaucratic cock up and political cowardice, so I think you’ll be in for a very long wait or completion (if ever) as I see people my age teaching their kids imperial (I’m 35).


  3. And what is the view of the British Monarchy on this issue?
    Is the recent announcement giving the birth weight of Princess Charlotte as eight pounds three ounces an indication that all members of the Royal Family prefer imperial units?

    The UK is part of The Commonwealth, Her Majesty Queen Elizabeth II is Head of this worldwide organization. All nations in the Commonwealth except the UK are metric.

    ‘ The Queen has been Head of the Commonwealth throughout her 60 year reign. This is an important symbolic and unifying role. As Head, Her Majesty personally reinforces the links by which the Commonwealth joins people together from around the world. ’ See link:


  4. I am not sure I would put athletics on the fully metricated list. Yes, internationally orientated events are in metric because that’s the international norm. Many small events are in kilometres (5k, 10k etc.). However, I see so many marathons and half marathons which are advertised in miles, the media reporting on them in miles etc. It makes me wonder whether the official body, UK Athletics, is fully metricated.

    As for next steps. While I agree that the situation on the roads is a big problem, it’s also the hardest and most expensive to fix. I would first concentrate on the many smaller things that can be fixed and that are achievable, even under the current government.

    First, I’d definitely like to see the square metre becoming the norm. It is the norm among architects and house builders whereas the square foot appears the norm among estate agents. Probably helped by the fact that the latter produces bigger numbers. It’s probably time Trading Standards were made aware that advertising property in square metres is the law, as recently confirmed again in Parliament.

    Second, people’s weight in kg. Considering every official place is already using metric for weighing people this requires mostly a behavioural change. That can be achieved without involving politics or blocking by luddites.

    Third, people’s height. See weight, although I have a feeling this might be harder to change than weight.

    Fourth, end translation into imperial in the media from metric sources. I would give up on convincing the Daily Express and Mail (the HSBC Telegraph could fit in there but considering it is only read by pensioners I’d say it’s largely irrelevant to change the future of the country). It would be great if the other big media institutions would stop translating news, science and technology figures that started of in metric into imperial. Not in imperial-only, not metric with imperial in brackets, just metric only. It saves them time, effort and the risk of conversion errors.


  5. @Erithacus:

    What you’ve said regarding imperial usage is true as far as it goes. The problem is that there is much more imperial usage than the areas you’ve listed, not only in the UK, but around the world. Much of this imperial usage stems from the fact that the British, followed by the Americans, set standards that are now embodied in many aspects of our lives. Such standards and usage serve to inhibit full metric conversion, and even results into ‘creeping imperialism’ in otherwise metric countries.

    Examples may be found as follows:

    – Construction: The construction industry in the UK is essentially metric, even at the DIY level. Yet plumbing pipe sizes are imperial, used around the world (I was quite surprised some years ago when undertaking a feasibility study for a German company, using German drawings, yet all plumbing sizes were in inches); likewise door sizes, where a door may be specified as being 762 mm wide, but this is of course a soft conversion from an imperial dimension. And while I can buy a sheet of plywood that is 2400 x 1200 mm, I can only buy a sheet of corrugated roofing that is 2440 x 1220 mm.

    – Automotive: the UK traffic sign issue you have already touched upon. But around the world, wheel sizes are in inches. There was an effort to express these in mm, but that seems to have fizzled out. Another area where imperial dimensions are found is in automotive hoses – the air-conditioning pipework on my very French Citroen is all marked in fractions of an inch.

    – Air transport: We can blame the Americans for the fact that air traffic control works exclusively in feet, while airlines and aircraft manufacturers still measure distances in nautical miles (even though – hopefully – there is nothing nautical about aircraft). Further, many standardised aircraft components – such as refuelling nozzles – are dimensioned in inches.

    These are just a few of the areas which contrive to prolong imperial usage in the UK. Other countries – except the USA – don’t have this problem, as they accept the use of imperial in these areas as an exception to their normal way of measuring things. We in the UK use this to justify the continuing use of imperial in almost every aspect of our lives. A hard problem to solve to be sure.


  6. An acquaintance of mine made a living in the late 1990s by visiting countries in Europe lecturing on the subject “How not to privatize your railways”. His services were particularly in demand after the Hatfield crash of October 2000.

    Alas, there seems little scope for such enterprise using this sad story of the UK’s bungled metric transition. With 98% of the world’s countries now nominally metric, only the USA might learn lessons here but is often reluctant to accept advice from others.

    Perhaps the only country that could benefit from studying how we arrived in this costly muddle is the UK itself. As has been pointed out, there is no sign of that at the present.


  7. The ultimate solution is of course for the USA to metricate since every holdout would disappear rapidly (assuming we followed the Australian example). Alas, that seems even less likely than for the UK to extricate itself from its muddle.

    It also seems clear to me that speaking of and reading dimensions in metric that are soft conversions from Imperial is still a far sight better than using the original Imperial dimensions. Using metric even in soft conversions at least reinforces metric usage (since most people won’t know of or relate to the original dimensions in Imperial).


  8. @John
    Plumbing in the UK has been metric for decades. Just enter “plumbing supplies” in your search engine, and look for any plastic or copper piping, or fittings.


  9. It is fifty years today that the change in Government policy was announced:
    ” … the Government consider it desirable that British industries on a broadening front should adopt metric units, sector by sector, until that system can become the primary system of weights and measures for the country as a whole.”

    Fifty years ago:
    * currency was £sd;
    * there were just three terrestrial TV channels (all b&w) and no satellite;
    * the only electronic computers were huge main frames kept in air-conditioned rooms;
    * air travel was for the wealthy – the jumbo jet was a few years into the future;
    * Britain had had its application to join the EEC rejected a few years earlier and would wait seven more years before applying again;
    * the Berlin Wall was just three years old;
    * there were no SNP MPs;
    * every Commonwealth country used Imperial as its primary system of measurement.

    Strange that Imperial road signs should have survived in the UK to remind us of a vanished world.


  10. @ Leo

    The examples you give are obviously highly desirable, but they are not within the power of government to change directly. However, road traffic signs clearly ARE a matter for the government. Moreover, they are so ubiquitous and prominent that they are a constant signal and reminder that the UK is not fully metric, and that you cannot operate effectively in the UK without knowing and using imperial measures. Arguably, if the road signs were converted, people would become accustomed to seeing distances, dimensions and speeds exclusively in metric units, and imperial usage would tend to fade away – rather as gallons and Fahrenheit are doing.

    That is why I think that converting the road signs is the key to further progress.

    BTW it wouldn’t be all that expensive – perhap £100 million. Whether you think that is a lot or a little depends on whether you want to do it or not. Compare it with the cost of HS2.


  11. @Erithacus
    you say “BTW it wouldn’t be all that expensive – perhaps £100 million. Whether you think that is a lot or a little depends on whether you want to do it or not”.

    Given that data shows around 35 million cars registered for use on UK roads and even my little old tin box car nets £12 month in ‘road tax’ that is £420 million a month paid in by motorists. This would suggest £100 million would be around 7 days road tax, not including fuel duty and other levies. 7 days would be around 2% of one years revenue v a lifetime of saving.
    Not a very scientific figure, but a paltry sum in my view. This cost argument is quite simply not valid, even with the DfT own daft figure of some £460 million or whatever it was. Lets just do it.


  12. @Erathicus

    I would say your comments are “spot on”. My contact in Ireland told me in response to my query last year that the conversion of road signs to km and km/h there noticeably accelerated the mental shift to metric in that country.

    I also notice that Canadians regularly use kilometers and kilometers per hour despite the very heavy “Imperial” influence of the USA right next door. The same is true for their near-universal use of Celsius instead of Fahrenheit for temperatures.

    Converting UK road signs would signal the final turning point towards metric. That is why the Luddites in Westminster resist it so mightily. It is also why I hope, if the Scots do choose to become independent, that they quickly convert their own road signs so that the rest of the UK gets a final push in that direction as well.


  13. If we’re waiting for our younger “metric educated” generations to finish the job gradually we’re going to be disappointed.

    Despite my best efforts with my own son who is now 18, he has had more than enough imperial exposure during education that he occasionally slips into inches and stones. My two step daughters are even worse, the eldest who weighs her two dogs in stones despite everything veterinarian seemingly being metric – a fact that I was extremely embarrassed about trying to buy flea treatment on one occasion getting the weight from her by text message in stones and then having to convert back!

    My younger friends and colleagues in their 20s and 30s seem no different. Last year I was discussing something with a friend of my own age (I’m 47) to hear a friend in his early 30s say “Listen to the old dudes, speaking in metric”.


  14. @Ezra

    It’s a nice thought that the Scots, post independence, might push the rest of the UK in the right direction towards metrication, but I am afraid to say I believe you are barking up the wrong tree. If such a scenario were to happen, it would be years, possibly decades away, and converting the road signs would probably be the least of the Scots’ worries. Apart from which, I don’t believe it will happen. What the UK needs is some sensible people in government to come up with a plan for closing the major loophole in the metrication programme and providing the extremely obvious missing link of converting the road signs. I am pleased that others here share the view that I have been putting forward for some time, that converting the road signs will provide the mental nudge and tilt the balance once and for all. I have lived most of my life in fully metric countries, having grown up in the UK, and I can tell you that the UK’s imperial road signs are the biggest fly in the ointment to any desired shift in perception and use of metric. People take their cue by what they see around them. They are shaped by what they see around them. If it will mean, as some seem to think, a ‘cultural’ shift (their term, not mine), so be it. Decimalisation was a cultural shift. The vote for women was a cultural shift. It just means ‘doing things a different way’. But the country would reap massive benefits in terms of technical skills and understanding.


  15. @BrianAC
    I spotted a flaw in you maths. You forgot (or didn’t realise) that only about 3% of the revenue raised from road tax is actually spent on transport, and that’s on ALL transport, not just on roads. Using your figures for revenue and for the cost of sign metrication would mean consuming 8 months’ worth of transport’s annual share of the road tax.


  16. @Charles P
    I did say it was not very scientific.
    However, the point was the amount raised from direct annual car taxation v the cost of converting road signs, not where it was all spirited away to.
    If DfT use this money for other purposes that is even worse, I have long held the view that this this is fraud.
    I also put ‘road tax’ in quotes, some (many?) years ago the government was challenged on this and ‘road fund license fee’ was changed to something else, a rose by any other name is the same thing.
    I also pointed out that this was only the figure of my paltry contribution, not that of HGV and MPV vehicles of which there are many.
    I also pointed out this does not include the revenue from direct vehicle fuel taxation, nor VAT on top of that (tax on tax). In all motor vehicles contribute a lot of money (probably rightly so, not an issue), we do however deserve a fair return (pot holes included (OT)).
    The fact remains there is a lot of money in the kitty, the money wasted in perpetual ‘work arounds’ for the metric muddle i.e. HGV 90km/h v 100km/h limiters, metric tachographs and Imperial speedometers, the multi million pound motor cycle test track just so brakes can be tested at 50km/h (32 mph), duplicate road signs, the perpetual effect of compromising school education, measuring in metres then posting ‘yards’. The list of expensive stupidities is lengthy.
    I have lived and worked with this for the full 50 years, I am less than amused, metric came as a vast relief from purgatory. I for one just wonder what the real maths and the real motive is, and why this fiasco is not resolved, a one off cost v a lifetime of confusion.


  17. @ Charlie P

    In the grand scheme of government spending, the cost of road sign metrication is still a pittance. Upgrading of road signs to modern units of measure would close the biggest hole in the metrication programme at very little real cost with spending which could be rolled out over a number of years. It would give an enormous boost and shine to UK plc.


  18. @BrianAC
    I suspect there would be a public/press outcry if it came to pass that the government were to make ANY money available for metricating the road signs while the physical roads themselves are in such desperate need of maintenance.


  19. @Jake
    Are we sure that the British people want “the biggest hole in the metrication programme” closed? I suspect there are many strong arguments, including economics ones, which would show that benefits of keeping imperial outweigh the benefits of compulsorily abolishing it.


  20. @ Charlie P: “benefits of keeping imperial outweigh the benefits of compulsorily abolishing it”

    Well, I believe some British manufacturers of zip fasteners do still use imperial machines, so you may have a yes-vote there. Otherwise, the arguments for updating the road signs have been comprehensively explained many times, so there is little point in repeating it all again.


  21. @Charlie P one of the things that is always missed here is that changing road signs from imperial to metric is not something that has to be costed as a one off project in this manner… road signs are regularly replaced as part of ongoing maintainence programmes and I seem to recall (correct me if I’m wrong anywhere) that the lifetime of any given sign is expected to be no more than 10 years. Also factor in that in recent years the number of signs showing distance has been reduced considerably so the actual cost of replacing imperial signs with metric ones (with the exception of speed limits) if done over the natural 10 year cycle need not be much more than has been already budgeted for.

    The only “big bang” cost might be speed limit signs but quite frankly there are other items in the government budget that are probably seen as being equally as unimportant yet are given considerably more money each year (I base this on UKMA estimates, not official government ones).

    The long term savings of road sign conversions would be in the little things we don’t think about – like the cost of car manufacturers having to provide MPH speedos for a relatively small portion of the world’s driving population, makers of other traffic-related equipment having to produce both MPH and km/h variants of things such as electronic signs, speed cameras and sat navs – even if it’s just software it still costs a lot of money to maintain. And then we would no longer have to educate our children in imperial measures which would save a LOT of time in the classrooms where other more important things could be taught, improving the overall education of our children and helping this country’s economic future.


  22. @Alex
    The point isn’t whether they are replaced or not, it is whether they should be metricated against the express wishes of the British people. You are right that total and absolute conversion will bring limited savings in some areas, but do not forget that the long-term economic impact is the sum of all savings minus the sum of all costs. We seem to have forgotten, or are ignoring, the latter.

    I am sure we could also cut education costs if we stopped giving children other life skills too. We could cut the manufacturing costs of clothes if we rationalised styles and cut the number of size increments made available – but at what cost to our society? What about limiting hair style choice to just one – the one that our political leader sports – that would yield massive savings, wouldn’t it?


  23. @Jake
    Have the arguments for NOT updating the road signs been comprehensively explored too, ever? Because, from what I have seen, the total metrication arguments rely largely on logical fallacies – and could equally be used to justify banning the use of the English language in the UK and requiring the use of French for all official and private communications.


  24. @CharlieP
    A governing party does what it sees to be in its interest. The wishes, express or otherwise, of the British people are a secondary consideration. Remember, the last Government sold off Royal Mail when surveys suggested that over 70% of the public were opposed.
    Hitherto, converting road signs to metric has not been seen by any governing party to be in its interest. One day this may change, perhaps when politicians realise that the current measurement muddle does the UK no credit and have the courage to do something about it.


  25. @derekp
    Yes, I agree that there are some things that the “governing party” know mean so much to the British people that to defy the peoples’ wishes would likely put their future election results at risk. I also agree that not compulsorily abolishing current imperial usage (including miles/yds/ft/in on road signs) is one of those things.

    That may change yes, but bullying and misleading the public – as UKMA seem to be advocating – will, if anything, delay that change. We must wait until public opinion demands that change.


  26. @Charlie P perhaps a little misunderstanding of what I meant about the savings… when I said “little things” I didn’t mean “limited savings”, what I was actually referring to what could be quite large savings for the country as a whole and for individuals on things they don’t necessarily consider to be related to metrication.

    This plays into the other point you raise, that being the appetite of the nation (or lack of it) for change, in that leaving aside the cop-out excuse of “culture” and the selfish “personal choice” and “freedom of speech” questions, the supposed outrageous cost is the only reason a lot of people are against this conversion… most people frankly couldn’t care either way so long as it doesn’t cost a whole lot of money.

    Personally I think it all comes down to the perception of the “bottom line” and winning the war will be about making the public realise that they they won’t have to foot a massive bill but will reap the benefit.


  27. I have mentioned in the past that the British public may be much further ahead in embracing metrication than are British politicians. Two recent incidents lead me to further affirm this view:

    Incident 1: I have a rental property on residential street close to where it passes under an arterial road. The overbridge is very low – signs say Very Low Bridge, Check Headroom. While I was chatting to a neighbour, a tall white van screeched to a halt, then did a 3-point turn and went back the way he had come. The neighbour said that until they changed the signs, tall vans (no lorries/trucks on this street) used to hit the bridge once a week, now this hardly ever happens. The bridge height sign used to be imperial only. Around September last year, the sign was changed to metric/imperial – 2.4 m / 7′ 9″. The results speak for themselves.

    Incident 2: We were having some decorating done on our staircase and landing by a professional decorator, and he had with him a telescopic ladder, which my wife thought rather neat. The decorator said that it was very strong, especially as he admitted he was way overweight. I noticed that the ladder was rated for 150 kg. The decorator said that was well over his weight – he said he weighed 110 kg. Not a stone to be heard! (The decorator was 42 years old.)

    Fifty years is lagging behind the British public’s acceptance of completing metrication. All it needs is the government to recognise this fact, and push to complete the process.


  28. Charlie P says that any metrication of the road signs would be against the will of the British people. Even if that was true, I don’t think there would be massive opposition to giving dual measures on height and weight restriction signs.

    Really, though, I can’t understand what all the fuss is about. Australia changed its road signs in July 1974, and though people did fear that there would be carnage on the roads, it all went very smoothly. Now people are rather fond of the kilometre signs, especially when they feature our native animals:


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