Percentage Calculator
Work out a percentage of a number, what percentage one number is of another, percentage change, and adding or taking off a percentage.
New: please check your results.
- 20% of 80 is
- 16
What it does
Five everyday percentage sums in one place. Choose what you want to work out (a percentage of a number, what percentage one number is of another, the change between two numbers, or adding or taking off a percentage), enter the numbers, and the answer appears as a sentence.
How to use it
- What do you want to work out?
Choose the sum you need, and the boxes change to match.
- Percentage
The percentage to find, add or take off, for example 20 for 20%.
- Number
The number you're working from, such as a price or a total.
- Number
When finding what percentage one number is of another: the smaller amount, such as your score.
- Out of
The total it's out of, such as the maximum score.
- From
For a percentage change: the old or starting value.
- To
The new value.
Common uses
- Working out a sale discount, a tip or a pay rise.
- Turning a test score into a percentage.
- Comparing prices, bills or results from one year to the next.
- Adding or removing VAT. Try the VAT Calculator (UK)
- Pricing with a profit margin or markup.
The formula
Percentage of a number = percentage ÷ 100 × numberWhat percentage = number ÷ out of × 100Percentage change = (to − from) ÷ from × 100Adding a percentage = number × (1 + percentage ÷ 100)Taking off a percentage = number × (1 − percentage ÷ 100)Where:
- from
- use the starting value without any minus sign
20% of 80 is the same as 80% of 20: both are 16.
Worked example
To find 20% of 80, divide the percentage by 100 and multiply by the number:
- 20 ÷ 100 × 80 = 16
To add 20% instead, multiply by 1.2; to take it off, multiply by 0.8.
Questions people ask
How do I work out a percentage of a number?
Divide the percentage by 100, then multiply by the number. For example, 15% of 60 is 15 ÷ 100 × 60 = 9.
Why doesn't a 10% rise and then a 10% fall get back to where I started?
Because the fall is taken from the bigger number. 100 rises by 10% to 110, but 10% of 110 is 11, so it falls to 99.
What's the difference between a percentage change and percentage points?
If a rate goes from 2% to 3%, it has risen by 1 percentage point, but by 50% as a percentage change. Both are correct; they measure different things.
Last checked 25 October 2026