Percentage Calculator

How it works

1. 1Pick the calculation that matches your question — the four boxes below cover "X% of Y", "X is what % of Y", "X is Y% of what number", and the percentage change between two values.
2. 2Type into either box in a pair; the answer updates as you go.
3. 3Percentage change is shown as a magnitude plus a direction (increase or decrease) rather than a signed number, since "-20%" and "a 20% decrease" get misread against each other.

Common questions

What is the difference between "percent of" and "what percent of"?

"25% of 200" answers to a value (50). "50 is what percent of 200" answers to a percentage (25%). They use the same two numbers in a different role, which is why they are kept as separate boxes rather than one form.

Why is percentage change shown as increase/decrease instead of + or -?

A drop from 200 to 150 is a 25% decrease. Written as "-25%" next to an increase written as "+33%" (150 back to 200), the sign is easy to misread under a glance. Stating the direction in words removes that.

Percentage change from 200 to 150, then back to 200 — why are the two percentages different?

Percentage change is relative to the starting number each time. 200 to 150 is a 25% decrease (50 / 200). 150 back to 200 is a 33.3% increase (50 / 150). Same 50-unit gap, different base.

What happens if I divide by zero?

The two calculations that would need to divide by zero ("what percent of 0" and percentage change starting from 0) show a dash instead of a number, since there is no percentage a real value can be of zero.