Everyday & industry
Percentage Calculator
Calculate a percentage of a value, find what percent one value is of another, compare percentage changes, or add and subtract percentages.
Use this calculator for common percentage calculations including percentage of a number, percent change, percent difference, and adding or subtracting percentages.
Choose the calculation that matches the question you are trying to answer.
Calculations use the numbers you enter without currency conversion. Results keep full precision internally and apply your Decimal Places choice only for display.
Calculations run locally in your browser. Your inputs are not saved.
Choose a percentage calculation and enter your values.
About this calculator
Common Percentage Examples
These examples are static references; your results appear separately after you calculate.
- 15% of 200: 15 ÷ 100 × 200 = 30.
- 50 is what percent of 200? 50 ÷ 200 × 100 = 25%.
- Increase from 80 to 100: (100 − 80) ÷ 80 × 100 = 25%.
- Difference between 80 and 100: absolute difference 20, average magnitude 90, so 20 ÷ 90 × 100 = 22.22%.
- Add 10% to 150: 10% of 150 is 15; the final value is 165.
Frequently asked questions
What is a percentage?
A percentage expresses a value per 100. For example, 25% means 25 out of 100, or one quarter.
What is the difference between percentage change and percentage difference?
Percentage change uses a starting value as its reference, so direction matters. Percentage difference compares two values symmetrically using their average magnitude.
How do I calculate a percentage increase?
Subtract the starting value from the ending value, divide that change by the starting value, and multiply by 100. A zero starting value has no defined percentage change.
How do I calculate a percentage decrease?
Use the same change formula: (ending value − starting value) ÷ starting value × 100. For positive starting values, a negative result indicates a decrease; the calculator displays its positive magnitude as the decrease.
Why can’t percentage change from zero be calculated normally?
The standard formula divides by the starting value. Division by zero is undefined, even when the absolute change is known.
Can percentages be greater than 100%?
Yes. A part can exceed its whole, and a change can be larger than the starting value. For example, 300 is 150% of 200.
General-purpose mathematical estimates only. Percentage change from zero and a reverse decrease of 100% or more have no finite result. No accounts, database, AI or external API calls are used; calculations run locally in your browser, and inputs are not saved.