How to use it

Type the old number, then the new one. A plus sign means it went up. A minus sign means it went down.

The formula

percentage change = (new − old) ÷ |old| × 100

Example: sales went from 80 to 100. (100 − 80) ÷ 80 × 100 = +25%.

The other way, from 100 back down to 80: (80 − 100) ÷ 100 × 100 = −20%. The two are not the same, because each one is measured against a different starting number.

Common questions

Why can't the old number be zero?

Every change from zero is an infinite percent, so there is no useful answer. Talk about the plain difference instead.

What is the difference between percent change and percentage points?

If interest rates go from 5% to 6%, they rose 1 percentage point. The percent change is (6 − 5) ÷ 5 × 100 = 20%. News reports mix these up often.

How do I apply a percent to a number instead?

Use the percentage increase calculator to add or take off a percent.

Last checked: 2026-09-25