I don’t care, except for temperature. You’ll tear Fahrenheit from my <some joke about temperature> dead hands.
In terms of converting feet to miles or whatever, I don’t know, I think I’m usually working in one broad unit or the other. If the destination is 10 miles away, I don’t care how many feet or yards. If the area rug has to fit in a 9 foot by 15 foot room, I don’t care how many miles or leagues that is.
Brit here. I will regularly say things like “The tower is 500 metres away and 50 feet tall”. I’ll usually state my height in feet and inches (it’s a big deal being over 6 feet tall 
) but I only know my weight in kilograms.
I think the generation after me is not so conflicted / bi-curious though: younger people tend to use metric for everything. But they still need to know distances and speeds in miles though. 
Yeah I wish we had switched over comprehensively in one go.
It makes expensive screwups more likely when you have to flip back and forth between the two systems.
The primary cause of this discrepancy was that one piece of ground software supplied by Lockheed Martin produced results in a United States customary unit, contrary to its Software Interface Specification (SIS), while a second system, supplied by NASA, expected those results to be in SI units, in accordance with the SIS. Specifically, software that calculated the total impulse produced by thruster firings produced results in pound-force seconds. The trajectory calculation software then used these results – expected to be in newton-seconds (incorrect by a factor of 4.45)[15] – to update the predicted position of the spacecraft.[16]
At the time of the incident, Canada’s aviation sector was in the process of converting from Imperial to metric units. As part of this process, the new 767s being acquired by Air Canada were the first to be calibrated for metric units.[9]: 63–64 The fueler reported that the density of jet fuel at the time was 1.77, which was in lb/L, since other Air Canada aircraft used lb. Pearson and Quintal both used the density of jet fuel in lb/L without converting to kg/L:
For those willing to embrace the Metric system, how do you feel about changing to use standard international paper sizes as well?
Wikipedia: ISO 216 paper sizes
Since coming to Europe I have fallen in love with A4 sized paper. Slightly taller, and slightly narrower than “US letter”, it has the advantage of retaining the same proportions when folded in half. According to the article, nearly everyone in the world uses it except for the US and parts of Latin America. Seems like it should be adopted too when the public finally ready to make the change.
(Of course filing cabinets would have to be slightly wider, but I cannot think of any other reason why A4 could not be phased in now as the default paper size in the US.)
Not just filing cabinets, but everything else that’s currently sized specifically for American letter-size (8 1/2" x 11") or legal-size (8 1/2" x 14") paper: folders, envelopes, printers and copiers, etc.
And that’s how the other sizes are defined too. Cut an A4 sheet in half and you now have two sheets of A5.
Conversely, two A4 sheets side by side is the same as one A3 sheet.
(cutting and placing the sheets the “obvious” way)
Must be a bitch filing reports at NATO.
I am an American who transplanted to Europe several years ago.
Metric was an adjustment, but not too bad. It’s clearly a superior system.
Temperature was the hardest mental switch, as noted several times in the thread. I eventually had to brute-force memorize some key ranges, and I still consciously think about it. 5-10 is coat weather. 20-25 is nice. 30-35 is hot. 40 is fuck you I’m going inside. 
Distance and weight, though, easy peasy.
No way the US ever gets over itself enough to make the switch, though. The country will destroy itself in armed revolution before it ever adopts metric.
I’m sure someone is out there fleecing customers based on U.S. versus Imperial gallons, or similar…
This is the only part of metric that actually works and it is basically a gimmick. “Oooo, I can instantly tell how many millimeters in a kilometer”. Yeah? How the fuck many times have I ever wanted to know how many 1/16 of an inch are in a mile?
Kilometers vs miles - a draw, slight edge to miles for longer distances.
Yards vs meters - a draw. Yards/meters are for sports only. Football, golf, track and shooting. Even warships range their guns and torpedoes in yards/meters. We don’t divide it any further!!! Yard/meter accuracy is all that is needed.
Feet vs what? - Metric doesn’t have a unit. Short people are 5’. Tall ones are 6’. No one needs to be 1.67 anything.
Inch vs mm - inch wins. When I hold something in my hand I want it to be 3 or 4 somethings, not 75 or 100.
For practical machining nothing beats 1/000" It’s perfect for everyday accuracy. A millimeter is way too big. A tenth of a millimeter is too big. .01 millimeter is too small.
Metric people overlook the fact that we don’t use all those units at the same time! Miles are given in miles and tenths or fractions. We don’t say, “One mile, 300 yards, 6 feet and 2 and an eight inches”.
Machining/assembly is in inches and decimal inches. 75 and 3/8" is listed as 75.375 inches. No different then metric.
The only thing that uses feet, inches and fractions is home building and even then it is inches and decimal inches for commercial use.
As a comment on memorization: 25+ years ago, I asked the girl a the deli counter for eight ounces of roast beef. She had no idea what ounces were because she sold roast beef in hundreths-of-a-pound. My late grandmother was worried about carrying around a paper that listed Fahrenheit & Celcius. “No, grandma, you just have to learn that 25C is a nice warm day and that at 30C you need to turn on the A/C.”
As someone who grew up in a place where Miles/Feet/Pounds/Gallons were something my grandparents remembered and were mocked for pining for, and who has spent a month a year in a place which they were never used, I find this whole thread filled with Americans telling me that without Feet, Miles and Fahrenheit degrees we couldn’t know whether you’d need a jacket outside, whether you were tall or short or how far you triple jump, quite absurd.
Forecasts don’t, but present and past temperature reports are given in tenths of a degree Celsius. It’s kind of pointless to give forecasts in fractions of a degree as that’s false precision – no forecast has that degree of accuracy. It’s kind of like when the media converts between metric and American for everyday approximations – i.e.- “after the accident the car skidded down the road a further 10 meters (32.8084 feet)”. 
Digital thermostats generally display the temperature in tenths of a degree Celsius, and heating and cooling set points are in increments of 0.5 Celsius degrees. There may be exceptions but this is more or less the common standard.
As I understand it, the movement to switch to the metric system here in the United States started back in the late seventies. It fizzled because we simply didn’t have the fortitude to go through with it. Only the United States, Liberia, and Myanmar are left as holdouts. It’s embarrassing.
A few years earlier than that, but yes. From Wikipedia:
As mentioned above, I remember lots of class work I did in grade school, around 1976-1978, around learning the metric system.
Why make a switch? In the US we use both. Lots of tools are in metric. Science always uses metric. Why not use both? I prefer Fahrenheit for describing sensible weather - 0 deg is very cold, 100 deg is hot. I like miles too. Typical driving speed is 60 mph (96 km/h). So it’s easier to estimate how long it takes to get somewhere using miles.
You could probably just use 100km/h to make it easy to figure how long.
The reason why the US hasn’t switched over is quite simple: we’re very large and very wealthy. We don’t have to adapt to others.
How I feel myself, is that you can stick your meterstick up your ass (collective you). I’m already being forced absolutely against my will into the abominable future of having a computer inserted into my brain for my personal shopping convenience. I have dyscalculia and I cannot manage even the numbers I have been accustomed to my entire life, much less a whole set of pointless new ones.
I married a guy who at times actually was a rocket scientist, although mostly he just tormented innocent particles by shooting them through gigantic tunnels. He swims in metric. I write stories, feed animals, sing songs, make artistic shit. I have no need for a new system of measurement.
“If Centrigrade confuses you as very well it might
nine-fifths plus thirty-two will give result in Fahrenheit.”
The US has a sufficiently large internal market to be able to tell everywhere else to go to hell.
What size to boards come in metric? A 2" x 4" is 1 1/5" x 3 1/2" or 3.8 cm x 8.9 cm.
4 cm x 9 cm should work. I don’t know what changes would be necessary at lumber mills.