MATH · FREE TOOL
Percentage calculator
Find a percentage amount, ratio or signed percentage change.
Your inputs
Enter your values, then calculate.
Decimal-point numbers; displayed rounding does not change internal values. Calculations stay on this device.
YOUR RESULT
Make the numbers clear.
Save calculation JSON ↓Calculation breakdown
Scroll sideways to see every column. You can also focus the table and use the arrow keys.
How this calculation works
a percent of b=a÷100×b. a as percent of b=a÷b×100. Change from b to a=(a−b)÷b×100. A zero baseline is undefined. Negative baselines retain their sign and can be difficult to interpret.
Check the assumptions
Use the stated units and conventions. This tool supports the workflow described here; it does not infer missing information or outside rules.