Percentage Increase Calculator
Find the percent change between two numbers — increase or decrease.
✓ updated June 2026
Formula: (final − initial) ÷ |initial| × 100 = (100 − 80) ÷ 80 × 100
Results are estimates for information only, not financial advice. See how we build and verify our calculators.
Enter where a number started and where it ended to get the percentage change — positive for an increase, negative for a decrease — along with the absolute difference and the exact formula used. Handy for price changes, salary hikes, traffic growth and test scores.
How to use the Percentage Increase Calculator
- Enter the initial value.
- Enter the final value.
- Read the percentage change, the absolute change, and the worked formula.
Frequently asked questions
What is the percentage increase formula?
(final − initial) ÷ |initial| × 100. For example, going from 80 to 100 is (100 − 80) ÷ 80 × 100 = +25%.
Why can't the initial value be zero?
Percentage change measures growth relative to the starting point — with a starting point of zero, any change is infinite, so the result is mathematically undefined.
Is percentage increase the same as percentage difference?
No. Percentage change is directional (from initial to final); percentage difference compares two values symmetrically against their average. This tool computes directional change, which is what most people mean.