Percentage Calculator
Pick a mode, enter two numbers and get the percentage result.
Result
30
- How it's computed
- 30
The formulas
- X% of Y = Y x X / 100
- X is what % of Y = X / Y x 100
- Percentage change = (new - old) / old x 100
- Add X% to Y = Y x (1 + X / 100)
- Subtract X% from Y = Y x (1 - X / 100)
Frequently Asked Questions
What can this calculator do?
Five things: X% of Y, X is what % of Y, percentage change from X to Y, add X% to Y, and subtract X% from Y.
How do I calculate percentage change?
Subtract the old value from the new one, divide by the old value and multiply by 100. Going from 80 to 100 is a 25% increase.
Why is a 50% increase not undone by a 50% decrease?
The second percentage applies to a larger number. 100 plus 50% is 150, and 150 minus 50% is 75, not 100.
How are results rounded?
To 2 decimal places.
What happens if the base value is zero?
Percent change from zero is undefined, so the tool cannot give a result for it.
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Published