Percent means "per hundred" — out of 100. The little \% sign is just shorthand for "divide by 100", so a percentage is really a fraction whose denominator is always one hundred.

So 25\% means 25 out of every 100:

Reading the \% as \div 100 always works. It turns any percentage into a fraction over a hundred, which you can then simplify or write as a decimal.

Two percentages are worth remembering on sight. 100% is the whole thing — all 100 parts out of 100 — and 50% is exactly half:

Because everything is measured against the same 100, percentages make different amounts easy to compare — a score of 80% beats one of 65% no matter what the tests were out of.

See it on a hundred-grid

Picture the whole split into 100 equal squares — a 10 by 10 grid. Shade n of them and you have shaded n\%: exactly n out of 100. Step through it.

See it explained

Sal Khan unpacks what "percent" really means — per hundred — from the ground up.