Percentage calculator

Every everyday percentage question on one page. Type in any box and the answer updates instantly.

Free, no sign-up

Before you use it

Works well for

  • Discounts, price increases and tips
  • Percentage change between two numbers
  • Quick everyday math

Not the right tool for

  • Compound growth over several periods — use the compound interest calculator
  • Interest on loans — use the loan calculator

The formulas behind it

  • X% of Y = X ÷ 100 × Y. Example: 15% of 200 = 30.
  • X is what % of Y = X ÷ Y × 100. Example: 30 is 25% of 120.
  • Percentage change = (new − old) ÷ |old| × 100. From 80 to 100 is +25%.
  • Increase by X% = Y × (1 + X ÷ 100). Decrease by X% = Y × (1 − X ÷ 100).

A common trap

A 10% drop followed by a 10% rise doesn't bring you back to the start: 100 → 90 → 99. That's because the second percentage is applied to a smaller number. Use the percentage change line to check moves like this.

Frequently asked questions

How do I find the original price before a discount?

Divide the sale price by (1 − discount ÷ 100). A $75 item at 25% off was originally 75 ÷ 0.75 = $100.

What's the difference between percent and percentage points?

Going from 5% to 7% is a rise of 2 percentage points, but a 40% increase in the rate itself.

How do I add sales tax?

Use the "increased by" line with your tax rate.