> And how does it help to say "hey can you pick up 3.8L of milk?" If packaging sizes don't change then we'll still call it a gallon and we won't have "converted" at all.

I'm with you on everything but this. The imperial system allows retailers (and/or consumer good manufacturers) to take consumers for a giant ride. I have lived in both USA & EU, and in the USA I just give up entirely on comparing goods in a supermarket. With the metric system there's nowhere to hide, and I can compare all products, whether you use ml or l, mg or g or kg. In the USA different manufacturers will use any odd denominator they can come up with and after about two weeks of normalizing fractions every time I went shopping, I gave up.

Even the little tags supermarkets add to try and help you, aren't enough. Many shops use a different denominator, and even a single shop will vary internally. Something as simple as comparing the price of bacon becomes a middle school math problem.

I hate corporate greed, I am partial to pointless mental exercise like math, and I am very stubborn. I don't want to speak for other people but something tells me I'm not the only one who has given up on this battle. Retail customers have more power in the metric system.

For everything else though yes I agree who cares. Except °F which is actually better. :)

> The imperial system allows retailers (and/or consumer good manufacturers) to take consumers for a giant ride.

That's a really interesting point. However, ultimately I actually don't think it has anything to do with imperial vs. metric, but just consumer culture.

In Europe, when you order a drink the menu tells you how many centiliters it is. In the US, it's just small-medium-large-XL, which every location defines however they want. And in the US, the difficulty in comparison doesn't have anything to do with imperial units -- it's that one package of tomatoes is defined by volume while another is by weight, and the loose bell peppers are priced per pepper while the packaged ones are priced per weight, and so forth.

Switching to metric wouldn't change any of that.

That's a problem that can seemingly only be addressed by legislation -- e.g. that strawberries and tomatoes must be sold by weight not volume, or that selling produce by the item must also accurately list the average item weight.

Your post reminds me of the additional problem of "The Serving" which is a unit of measurement entirely conjured up by the food manufacturer to serve as the denominator when listing required nutritional information.

A normal 50g bowl of your sugary breakfast cereal too unhealthy? Just define a "serving" as 20g and cut all your bad numbers by 2/5! Problem solved! Is your bag of chips full of salt? Just invent a "Serving Size" of three chips and you don't have to draw attention to yourself on the nutrition label.

Letting companies define their own units of measurement seems to be a totally preventable regulatory mistake.

Indeed, it's something the EU prevented. There are regulations on what the standard serving size is, and other regulations specifying how the item must be priced -- so all the milk says "per litre" under the price tag in the supermarket, even the fancy one in a tiny bottle.

There were also preferred size regulations, which was meant to make it even easier. Breand could only be sold in multiples of 400g. I think this was relaxed, but it's still present for some things. A standard bottle of wine is always 75cL, for example.

I was thinking 50+50 years, but ok 10+10 years is even better. I mean, if you do it gradually enough, the cost approaches zero, so is it worth "almost zero" to have a standard measurement system across the globe? Maybe?

Nothing stops us from enacting generous legislation mandating the switch to metric by the year 2125 or something. You'd have to have intermediate milestones of course, or everyone would just do nothing and wait until 2124 and then complain endlessly about how the transition is so costly and we can't possibly do it in a year, and so on.

But this is the USA, where we can't seem to do anything that takes longer than a quarter, and our entire country's major priorities change every 4 or 8 years.

So if everyone knows everyone will be whining, you could just as well announce the transition tomorrow and get it over with in a year.

As if Americans don’t find a reason to whine every bloody day.