Otaku Dojo Tools
English

Percentage Calculator

The Percentage Calculator answers the four most common questions: "What is B% of A?", "A is what percent of B?", "What is the percentage change from A to B?" and "What is the price after B% off A?". Results appear as you type, together with the full formula so you can check quotes, grades, growth rates and discounts.

  • Free
  • No sign-up
  • Runs in your browser
Options
Result
The result will appear here
Results appear as you type

How to use the Percentage Calculator

  1. Choose the calculation type.
  2. Enter two numbers — the field labels change with the calculation.
  3. The answer, related values and formula appear instantly.

Examples

Sales growth

Input
Last month 1,280 → this month 1,600
Output
Increase +25% ((1600 − 1280) ÷ 1280 × 100)

25% off

Input
Price 1,280, 25% off
Output
Sale price 960, you save 320

Specs & key facts

CalculationsB% of A, A as % of B, percentage change, price after discount
Change formula(new − old) ÷ old × 100%
PrecisionUp to 4 decimal places
FormulaShown for every result
ProcessingIn your browser
PriceFree, no sign-up

FAQ

If something rises 50% and then falls 50%, is it back where it started?

No. 100 up 50% is 150; 150 down 50% is 75, because each change uses a different base.

What is the difference between percent and percentage points?

An interest rate moving from 2% to 3% rose by 1 percentage point, but by 50 percent.

How do I calculate what percent A is of B?

Divide A by B and multiply by 100 — for example, 45 out of 60 is 75%.