The way you described it looked like trolling, hence the downvotes, I think. But your thinking is sound. People most commonly count their alcohol in shots and shot-equivalents.

1.5oz = 44ml. Most liquor is 40% ABV. That's ~18mL of pure alcohol.

The average beer bottle size is 330mL - 500mL, at 4-6% ABV. Again, that's in the 16-25mL of pure alcohol range.

Maybe rounding to 20mL might be a better definition of a "unit" of alcohol. It's still easy enough to do math with, and more representative of what people consider one drink.

I dunno, the previous system is pretty easy to figure out, whereas I have no idea how to calculate my consumption using US units.

Not sure if serious or trolling.

Not sure if stupid or missing the point in a reasonable way. I'm just saying 10 mL is not a drink. 18 mL is a drink.

18ml is not a drink in England, which is the place we're talking about for 'units of alcohol'.

In fact, most countries don't use the same measures for alcoholic drinks as the USA does. I'm surprised you don't know this.

A "drink" in England is a pint of lager, making the 10 ml measure even sillier. What are you talking about?

No, it isn't. There are several different kinds of drinks in England. Again, you seem to be talking about a subject you clearly know nothing about.

For example, you thinking that England uses imperial measures for its shots. It doesn't.