About this calculator
This is a free online percentage calculator built to be fast, accurate and private. Every calculation runs entirely in your browser — no data is sent anywhere, there is no sign-up and there are no limits. The tools cover the most common everyday percentage questions: finding a percentage of a number, expressing one number as a percentage of another, percentage increase and decrease, and working backwards to an original total.
The formulas
Percentage of a number: result = (percent ÷ 100) × numberNumber as a percentage: result = (part ÷ whole) × 100Percentage change: result = ((new − old) ÷ |old|) × 100