Percentage Calculator
Every common percentage calculation, instantly
Calculation type
Inputs
Result
30
Formula
20% × 150Quick steps
Pick a calculation type
Five common percentage problems are supported. The inputs adapt to the type you choose.
Fill in the numbers
Each input updates the result instantly. Your values persist when switching between calculation types.
Copy the result
The formula used is shown next to the answer, so you can verify the math yourself.
Frequently asked questions
What is the difference between percentage and percentage point?
Percentage is a fraction of a number (5% of 200 = 10). Percentage point is the arithmetic difference between two percentages (a rate going from 5% to 7% is a 2 percentage-point increase, but a 40% relative increase).
Can I use this for tax calculations?
Yes. Use 'Increase X by Y%' to add sales tax. Use 'X is what % of Y' to determine an effective tax rate after a deduction.
What about negative percentages?
All five modes accept negative numbers. Negative results are kept negative (a -20% change is a 20% decrease).
How precise are the results?
We compute at JavaScript's native double-precision (about 15 significant digits) and display up to 6 decimals. Round to the precision your use case needs.