99% of it is metric. I think the biggest outlier is home care, where you go visit some grandma who's actively offended by metric, so if you tell her to take 7.5mL of something she'll just do the deer in the headlights thing, then shove the bottle up her ass.
Tell her instead that she needs to take 3 Mountain Dew caps full and suddenly she can follow instructions enough to not kill herself.
I know it should be obvious and maybe I missed the sarcasm, but the teaspoon unit is in no way the same as an actual teaspoon utensil. I also don't use my own feet to measure length.
I didn't think that was sarcasm, it's just such a jacked up system of measurement that he's not confident it doesn't change with borders, which is honestly a pretty reasonable point of uncertainty.
Until you start looking at old stuff and have you figure out if they were working with the "millions scheme" or "thousands scheme," and if "1 billion" is equal to 1012 or 109
Psi is used a lot in engineering. But honestly, pressure units are a bit of a mess. The metric unit is a Pascal, which is fundamentally defined as a Newton per square meter – unsurprisingly, that is an incredibly small quantity of pressure. It’s roughly 101,500 Pascals for standard atmospheric pressure. You’ll typically see pressure written in either kPa, MPa, or bars (1E5 Pascals) within a metric framework. For perspective, it’s 14.7 psi (lbs per square inch) for an atmosphere.
And personally, I think all of these are pretty silly when we could be using 1 atm instead, which is literally defined as standard atmospheric pressure. It’s a much easier way to visualize and intuitively grasp pressures.
BTU is another fun one. It’s the energy needed to raise 1 lb of water by 1 degF. Calorie is the energy to raise 1 g of water by 1 degC. Both are very pragmatic definitions and have a degree of intuition. Then they’re the metric unit, the Joule, which suffers from the same issue as Pascal. It’s the work done by a 1 Newton force pushing an object 1 meter. Once again, pretty small.
It works fine when everything around you is in those numbers. The scale for medications might be set to mg, or injections in mL. The bottles for both are labeled the same way. Everything works together, and you don't really have to think about it.
Part of the problem with converting everything to metric is it really needs to be everything. You can try talking about driving distances in km, and your gas tank in L/100km, and your speed in km/hr. However, the interstate highway signs will still be in miles, you buy gas in gallons, and the speed limit signs are in mph. This isn't a case where you can just choose to use the metric system as an individual, because the whole system works against you.
That is understandable, I was surprised that metric is actually used somewhere. Use in pharmacy also explains why in Hollywood stoner comedies they used grams, which always confused me.
It's used all over the place in the US. It's usually a weird, thoughtless mixture. Milk is sold in gallons, soda is sold in liters.
In fact, you'll find exceptions in most countries once you start looking for them. Just a matter of how prevalent the metric system is; nobody is 100%. Most common exception is car tires because of how industry standards work.