Really though, the most ardent defence of USC units is fuelled by great amounts of Copium. The US Customary set of measurements is several independent systems of measurements which often radically different origins and sometimes irrational conversions, all stacked upon each other and dressed in a trench coat. For instance, the mile has Roman origins while the inch and foot were defined separately, much later, and with a lot of regional variation. The French foot was longer than the English foot, which is why Napoleon was listed as 5'2" tall while he was actually closer to 5'9", or 1.71 m, which was pretty average for the time.

Which one of these is more straightforward to calculate:

• You are tasked with installing a rail along a 1 mile long bridge. You know you can use two half inch bolts to affix it every three feet. How many bolts do you need?

• You are tasked with installing a rail along a 1,5 km long bridge. You know you can use two M12 bolts to affix it every metre. How many bolts do you need?

Conversions within dimensions in USC require you to memorise arbitrary conversion numbers. Conversions within dimensions in SI require you to move the comma a few spots.

Besides, if the US Customary system of units is so great, why did most of the world voluntarily switch to SI units?

Everything in America except building trades has transitioned to metric already.

Even our imperial units are defined in metric.

But... PLEASE don't tell our citizens. It will all be fine as long as we don't tell them!

@Zerush Too much hassle to change to metric

For anything construction-scale, all supplies sold in the US are based on 4x8' sheet goods and 16-24" on-center framing. I also concede that king George the 74th's foot length is more human-scale when dealing with large measurements: 20 feet vs 6096 mm. I still use metric when possible, however - I find it easier and more accurate.

For EVERYTHING else I've switched to using metric.

Context: I grew up in the US using imperial units and only pivoted to the metric system in 2020. If I grew up thinking in metric and building supplies/standards used it, it'd be superior in every way.

TL;DR I like my imperial/metric combo tape measure.

I've read that it is more easily divisible than metric.

Divide a meter by 3 or 4 and get ugly numbers but a foot or yard divide by 3 or 4 quite cleanly. And so on.

Depending on your application this can be very helpful.

I’m terrified of driving the day they move the US from miles to kilometers. People go well over the speed limit as it is. I can only imagine how many people would read the kilometer per hour speed limit as miles.

It's easier for handling real things.

Try doing woodwork in feet and inches for a day. Try it in metric for a day. You'll see what I mean.

It was crafted for the human-scale, whereas metric was worked out on paper by French philosophers.

Metroids itt btfo, malding, fractionally mogged upon.

There are (huge) costs to retooling production to move from imperial to metric. Even if a company wanted to make that move they'd have to transition in phases and will likely end up with additional equipment to maintain. There's also significant training for workers (who will likely commit errors in the beginning) which will impact production. And what happens to the old equipment? I'd guess a significant portion of that would end up getting scrapped and landfilled.

Perhaps I'm biased, but sometimes it's easier to work in fractions. Also, setting room temp is objectively better in F. I can tell the difference between 74 and 75. That said, I'm also a scientist so I'm permitted these opinions.