I GOOGLE "why doesn't the USA use the metric system?" The reply I get? "Time and money." Makes no sense to me. Know why?

The metric system was invented in France after the French Revolution, by which time the Americas were already well populated with a motley assortment of nationalities each with their own systems.

France did that because her own national measurement system was anything but a system! It was an unholy mess of regional trade units that made commerce across larger distances very difficult. The odd thing though was that they tried to be too clever and base the metre on a fraction of the Earth's circumference, not easy to measure accurately even now; rather than on something more tangible like the Nautical Mile.

The Imperial Sytem with some units altered, became de facto standard in America probably due to the large proportion of settlers from Britain and Ireland; and the many imports from those countries at least until American industries could become established.

I think the French did send an official Metre Bar standard, but it was never adopted for everyday trade.

American scientists and some engineers do use the Metric System, or more accurately its SI off-spring, and I have noticed NASA Flight Controllers giving commentaries on planetary landings do now call the altitudes and speeds in metres and km/hr. 

If you buy a car in the USA that has been imported from anywhere else in the last few decades it will almost certainly have been built to metric dimensions, and you'd need buy metric-sized spanners etc. to service it. 

I was in grade school when Canada switched from Imperial to Metric - I was agaist it back then but now I am glad we switched. The only way the Google time and money answer makes sense is if it means it costs America and most of its trading partners time and money converting from metric to Imperial. Back when Canada was about to switch to Metric - America was about to do it too but they backed out of the agreement at the last minute. Cheers!

Google’s answer kind of oversimplifies it.  First of all, it’s unpopular.  The polling on switching to the metric system is only 21% in favor of it.  That’s kind of a hard sell for politicians.  In fact, politicians who support it usually don’t get very far.  Lincoln Chafee is one of them.  It was part of his platform when he was running for the Democratic nomination for President in 2016.  He had a good platform.  I agreed with all of the points on his platform, but he got a whopping <1% of the vote.  

George H.W. Bush was another politician who supported switching to the metric system.  He even signed an executive order mandating it.  He was also a single-term President.  If George H.W. Bush would’ve won re-election, our road signs would be in metric, but the trade-off is that we might still be poking along at 110 km/h on freeways outside of cities and 90 km/h on all other highways.

George H.W. Bush’s executive order would’ve had us on the metric system by 1995, in which case I would have no memory of ever using anything other than metric.  When Bill Clinton was President, Congress sent him a bill to both undo the executive order on the metric system and repeal the national speed limit of 65 on freeways outside of cities and 55 on all other highways.

Bill Clinton signed it, so no metric system, but we’re also not creeping along at painfully low speed limits.  Most states aren’t anyway.  The only states that never increased their speed limits after the repeal of the national speed limit are Vermont, New York, Massachusetts, Rhode Island, Connecticut, New Jersey and Delaware.

This post was edited by Livvie at June 8, 2021 10:42 PM MDT