Leave off the word “metre” and it doesn’t matter whether you’re using metres or cm. You’re “one eighty-six”. Is that a lazy way of saying “one [hundred and] eighty-six”, quite common when talking about numbers in the hundreds, or the lazy way of saying “one [metre] eighty-six [centimetres]”, a common shorthand similar to shortening “six [feet] five [inches]”? The answer is it doesn’t matter!
Us metric people usually say it in meters. I’m one meter 86.
Leave off the word “metre” and it doesn’t matter whether you’re using metres or cm. You’re “one eighty-six”. Is that a lazy way of saying “one [hundred and] eighty-six”, quite common when talking about numbers in the hundreds, or the lazy way of saying “one [metre] eighty-six [centimetres]”, a common shorthand similar to shortening “six [feet] five [inches]”? The answer is it doesn’t matter!
Unless you’re reaaaally small
I’m one eighty six… kilometers!
I’m American and that’s how I’ve started giving my height. I’m 191.