Calculators
Percentage Calculator
Work out part of an amount, such as a 12% tip on a 850 bill.
Decimals are fine. Everything is worked out on your device.
Work out a percentage of a number, turn two numbers into a percentage, or find the increase or decrease between them. The formula is shown with your numbers filled in.
How to use this tool
Choose the kind of question you have, such as “What is X% of Y?” or “Percentage increase or decrease”.
Type the two numbers the question asks for. Decimals are fine.
Read the answer and the worked-out formula underneath, then copy the result if you need it.
How to use this tool
Choose the kind of question you have, such as “What is X% of Y?” or “Percentage increase or decrease”.
Type the two numbers the question asks for. Decimals are fine.
Read the answer and the worked-out formula underneath, then copy the result if you need it.
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The four percentage questions people actually ask.
Percentages turn up in tips, discounts, marks, interest and reports. Pick the question that matches yours instead of remembering which way round the formula goes.
- Four ways round
- A percentage of an amount, one number as a percentage of another, the change between two values, and adding or taking off a percentage.
- The working is shown
- Every answer comes with the formula and your own numbers filled in, so you can check it or copy it into homework or a report.
- Accurate to the last place
- Results are worked out at full precision and rounded only for display, so long chains of percentages do not drift.
Frequently asked questions
How do I work out a percentage of a number?
Multiply the amount by the percentage and divide by 100. For 20% of 150: 150 × 20 ÷ 100 = 30. Choose “What is X% of Y?” and the calculator shows that line with your numbers in it.
Why can't a percentage change be worked out from zero?
Percentage change is the difference divided by the starting value. If the starting value is zero, you would be dividing by zero, and any rise from nothing is infinitely large as a percentage. Compare the two amounts directly instead.
Is a 20% rise cancelled by a 20% fall?
No. 100 raised by 20% is 120, and 120 lowered by 20% is 96, because the second percentage is taken from the larger amount. This catches people out with discounts and share prices alike.
What is the difference between percent and percentage points?
If a rate moves from 20% to 25%, that is a rise of 5 percentage points, but a 25% increase in the rate itself. This calculator works on the numbers you type; be clear which of the two you mean when reporting it.
Does it handle decimals and negative numbers?
Yes. Decimals are accepted everywhere. Negative values work too, though a percentage change from a negative starting value is easy to misread, so a short note appears when you use one.