> Edit: Not sarcasm.

Heh. I think you'd be disappointed. I haven't heard of of any modern country seriously considering moving from metric to imperial units.

> They're sane and easily divisible into eighths and more with a single significant digit of the next smaller

Divisible maybe. But definitely not sane.

Let's take a look at lengths and weights for example:

How many inches in a foot? 12. Ok. Then it must be 12 feet in a yard. Nope. It's 3. How many yards in a mile? Guessing 1000 or 1200. Nope. Apparently 1760.

Let's try weights. Going up from ounces. Since we already did imperial lengths and saw there are 12 inches in a foot, guessing there should be 12 ounces in a pound. Wrong again. It's 16. Ok, so then 1 US ton should be 1600 pounds right? Nope, wrong again. Apparently it is 2000!

I grew up with metric then came to US and lived here for more than a decade. Apart from knowing how many inches in a foot I had to look up all the other ones because they are non-intuitive and don't follow any pattern to me. I can estimate how much is a yard, an ounce, a pound, an inch, and a foot. But again I could intuitively estimate things even better when it came to meters, kilometers and kilograms.

Your biggest complaints are that (1) metric units are not quantities you use in everyday life and (2) that you don't know how large a metric quantity is.

Both are just because you are unfamiliar with the system, people working with this system do not have this problem at all. Regarding (1), people don't care that a litre is too large too drink, they just know that a glass is 0.2-0.25L, so you can get 4-5 glasses out of a litre bottle. The benefit base 10 units is that they're easy to convert and use, people don't care if something is in cL/dL/L because it's just a comma placement away.

Regarding (2), people have a very good feeling about how big their everyday units are. E.g. a metre is about a step (large/small step depending on your size), that's fine for rough measurements, and about as (in)accurate as your "a foot is my forearm".

Half of 12 is 6, half of 1/4 is 1/8, I drill the hole at 6 and 1/8".

It's easy to get a fractional measurement of whatever is in front of you and immediately work with that measurement in your head then find the corresponding mark on your measuring tool. There is no reason the same system would not work with metric, it just seems to be more common with imperial units.

E.g. IKEA cabinets are 60 cm wide (90, or 120 for larger cabinets), common countertop depth is 60 cm, and so on.

That way we get to use sane and consistent units and we can easily see/measure the middle of a 60cm piece of wood or whatever.

It also tickles me how eyeballing these things is apparently something desirable. Whenever I work around my house I measure everything twice to be sure...

Not everything in the world is (or should be) provided by Ikea :)

Or the length of one's foot, even.

You're right about meters not being as good a "human scale" measurement as feet. The idea of average height being 1.8 m is pretty awkward on its face. Turns out, though, the metric world has settled on starting with centimeters, though. But it's not clear that this is better, because now you end up throwing around high magnitude numbers like "183 cm" rather than "6 ft".

Given that we're clearly comfortable going with a diminutive unit (viz. cm vs m), I've always thought it would be better for the world to settle on the decimeter as the reference unit instead. It's larger than a centimeter but smaller than a meter, which is what we're after, and it's about the width of one's hand, which is arguably a more natural choice for something "human scale" than the foot. The snag is that "foot" still rolls of the tongue a lot more easily that "decimeter". So we go ahead and say 1 dm = "1 hand". It's a great unit, because if we want, we can scale up or down to meters and centimeters with (base 10-derived) constant factors, which is so easy that anybody can do it in their head.

The only snag left is that "hand" is already in use as a unit. This turns out to be less problematic than it sounds, because the legacy hand is an obscure unit really only used in horse breeding. And we're in luck, because as its name suggests, the imperial "hand" is named after the span of one's hand (with fingers extended), so they're roughly the same—it's not as if you end up with one name for two wildly differing sizes. This is the same kind of "conversational equivalence" we get with a ton and a metric tonne. That is, in conversation you're basically never reduced to needing the speaker to clarify which it is that he or she means, because you just don't need that kind of precision—a ton and a tone are both two very large masses that are in the same ballpark as one another.

Perhaps most importantly, the transition from feet to hands is fairly straightforward in conversational use, because end up saying that "1 ft" equals "about 3 hands".

People make a big deal about pi versus tau, but getting widespread adoption of the "hand" as a unit seems to me to be a much more worthwhile cause, because it would have a much bigger practical impact on everyday life than tau ever would.

>Or the length of one's foot, even.

-If you're using size 14 (US; male), 15,5 (US; female), 48 (Europe), 12,5 (Mexico)...

The good thing about standards is that there's so many to choose from.

thus underscoring your point: we can't even agree on how to represent numbers, let alone measurements!

Don't get me started in "tiny pints" used in the u.s.