Percentage difference calculator (with working)
Find the percentage difference between two numbers, with the working, plus the percentage change.
What does the percentage calculator do?
This percentage calculator answers the three questions people ask most: what is X% of a number, what percent is one number of another, and by what percentage has a value gone up or down. Every result shows its formula, so you can check the working.
How to use the percentage calculator
- Pick the calculation that matches your question.
- Type the two numbers. Results appear as you type.
- Read the formula under the answer to see how it was worked out, and copy the result if you need it.
Your privacy
All calculations run in your browser. The numbers you enter are not sent or stored anywhere.
Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number. For example, 15% of 80 is 0.15 × 80 = 12. To find a percent of a percent, use the same box: 50% of 20 is 10, meaning 10%.
How does the percentage change calculator work?
It subtracts the original value from the new value, divides by the original value and multiplies by 100. Going from 80 to 100 is (100 − 80) ÷ 80 × 100 = a 25% increase.
Why isn’t a 20% increase undone by a 20% decrease?
Because each percentage is taken from a different starting value. 100 increased by 20% is 120, but 20% of 120 is 24, so decreasing by 20% gives 96, not 100.
What is the difference between percentage and percentage points?
A change from 10% to 12% is a rise of 2 percentage points, but a 20% increase relative to the original 10%. Use percentage points when comparing two percentages directly.