Percentage Calculator
Free percentage calculator. Find X% of Y, work out what percentage one number is of another, and calculate percentage change.
X% of Y
X is what % of Y?
% change from X to Y
Frequently asked questions
How do I calculate X% of Y?
Multiply Y by X, then divide by 100 — or equivalently, multiply Y by X/100. 20% of 50 is 50 × (20 ÷ 100) = 10.
How do I work out what percentage one number is of another?
Divide the part by the whole, then multiply by 100. 10 is what percentage of 50? (10 ÷ 50) × 100 = 20%.
How is percentage change calculated?
Subtract the original value from the new value to get the difference, divide that by the original value, then multiply by 100. Going from 50 to 65: difference is 15, so (15 ÷ 50) × 100 = 30% — a 30% increase. A negative result means a decrease.
Why can percentage change give a different result going backwards?
Because percentage change is always relative to the starting value. Going from 50 to 65 is a 30% increase, but going from 65 back down to 50 is only about a 23.1% decrease — the same 15-point difference is a bigger fraction of the smaller starting number.