Metric vs Imperial: which countries still use imperial?
A quick map of who uses which — and where metric beats imperial at scale.
Out of 195 countries, only 3 formally use the imperial / US customary system for everyday life: the United States, Liberia, and Myanmar.
The UK uses a confusing hybrid: road signs in miles, beer in pints, milk in litres, body weight in stones, and distances in metric at the supermarket. Canada is mostly metric but legally mandates imperial for some products (milk in quarts).
The metric system has two structural advantages:
1. Powers of ten. 1 km = 10³ m. 1 cm = 10⁻² m. No one has to remember 12 inches in a foot, 3 feet in a yard, 5,280 feet in a mile. 2. Unique prefixes. "kilo", "mega", "giga" mean the same thing everywhere — across mass, length, time, voltage, data, anything.
Imperial's redeeming feature is inertia: switching systems costs money and training, and the US has billions of dollars of road signs and recipes in inches and cups.
If you're converting frequently — say, working with international clients — a converter like the one on this site is faster than mental arithmetic, especially at scale (e.g. square footage to square metres).