Percentage Calculator

Solve percentage, what percent, and percent-change problems in one place. Free online calculator with formulas and step-by-step solutions.

Key formula

percent, ratio, and percent-change formulas

About this tool

Solve percentage, what percent, and percent-change problems in one place. Free online calculator with formulas and step-by-step solutions.

How to use this calculator

1. Choose the correct mode or direction before entering numbers.
2. Make sure your values match the expected units or date format shown in the fields.
3. Calculate once, then read both the final output and the supporting formula steps.
4. Round only after you understand the result so you do not lose useful precision too early.