Percentage Calculator
Work out percentages of a value, what percentage one number is of another, percentage change, increases, decreases and reverse percentages — with the formula shown for every result.
Percentage Calculator
Work out percentages, percentage change, increases, decreases and reverse percentages.
What is A% of B?
What is A% of B?
36
15% of 240 is 36.
(15 ÷ 100) × 240 = 36
How to use
The whole flow runs in your browser — nothing is uploaded.
- Choose a calculationPercent of a value, X is what % of Y, percentage change, increase, decrease, reverse percentage or percentage difference.
- Enter two numbersEach mode shows only the two fields it needs, labelled in its own terms.
- Read the answerThe result, a sentence describing it, and the formula with your numbers filled in.
- Copy itOne click copies the result for your report, invoice or spreadsheet.
- Every step runs locally in your browser.
Key Features
Percentages, percentage change, increases, decreases and reverse percentages. Everything runs client-side on your own device.
- Seven calculationsThe percentage questions people actually ask, each with its own labelled fields.
- Show-your-work outputEvery answer includes the formula with the real numbers, so the result can be checked.
- Discounts, tips and changePercent-of covers discounts and tips; the change modes handle growth, markups and reductions.
- Runs locallyExact decimal arithmetic in your browser — no spreadsheet needed, nothing transmitted.
Frequently asked questions
Percentage change measures movement from an original value to a new one — going from 250 to 300 is a 20% increase. Percentage difference compares two values symmetrically against their average, which is the right measure when neither value is an obvious starting point.
Use Percent of value for the amount (15% of 240) and Decrease by % for the final price (240 decreased by 15%). For a tip, Increase by % gives the total directly.
Reverse % answers questions like "60 is 25% of what?". It is the mode to use when you know a value and the percentage it represents, but not the original figure — for example when a price already includes tax.
The maths runs on the exact numbers you type and is rounded only when displayed, to a maximum of six decimal places. Increase and decrease modes also show the signed change.