About this tool

Measure the increase or decrease between two values.

Enter your values, run the tool and check the result before relying on it.

Method and example

The change is (new value − original value) ÷ original value × 100. The original value is the denominator, so changing the starting point changes the answer.

Going from 80 to 100 is a 25% increase. Going from 100 to 80 is a 20% decrease. The difference is 20 in both cases, but the percentage uses a different starting value.

Before you use the result

• A zero starting value has no ordinary percentage change.
• A rate moving from 20% to 25% rises by 5 percentage points, or 25% relative to its original rate. State which measure you mean.

Worked example

Original value

100

New value

125

Result for this example

25% increase
Difference: 25

Use Try an example to load these values. Enter your own values for your own result.

Read the method and examples

• Percentages, percentage change and discounts explained — Choose the correct denominator and avoid the common percentage-point and successive-discount mistakes.

Found a reproducible issue? Report it with a small non-sensitive example. Read our editorial and testing approach.