Percentage calculator
Pick a question, type two numbers and read the answer. It works with 12,5 and 12.5 alike.
How it works
- Pick what you want to know, for example X % of Y or the change from X to Y.
- Type your two numbers. A comma or a dot both work as the decimal mark.
- The answer and the formula appear right away. Press Copy to use the number elsewhere.
How percentages work
A percentage is a part of a hundred. To find 15 % of 80, divide 15 by 100 and multiply by 80, which gives 12. To find what percent 12 is of 80, do it the other way round: 12 divided by 80, times 100.
Percent change compares the new value with the old one: the difference divided by the old value, times 100. Going from 80 to 100 is an increase of 25 %, but going back from 100 to 80 is a decrease of only 20 %, because you start from a bigger number.
That is also why you cannot undo a 20 % discount by adding 20 %. To find the price before a change, divide by 1 plus the percentage (or 1 minus it for a decrease). The last mode does exactly that.
Everyday percentage sums made easy
Percentages come up all the time: a 30 percent sale price, a tip, a pay rise, the growth of your savings or a score on a test. Pick the question that matches your sum. X % of Y gives a share of a number, X is what % of Y turns a score into a percentage, and Change from X to Y shows a rise or fall.
A quick way to check yourself: 10 percent is the number divided by 10, and 1 percent is the number divided by 100. So 15 percent of 80 is 8 plus half of 8, which is 12. Two discounts in a row do not add up: 20 percent off and then 10 percent off is 28 percent off, not 30.
For prices with tax, use the VAT calculator, which also shows the tax amount itself. For a sum that undoes an earlier change, use Before the % change. For example, a price of 90 after 10 percent off was 100 before, not 99, because the discount was taken from the higher price.
Questions
How do I calculate a discount?
Choose Add or subtract %, pick Subtract, and type the price and the discount. A 25 % discount on 60 leaves 45.
What is the difference between percent and percentage points?
If interest goes from 2 % to 3 %, it rose by 1 percentage point, but by 50 percent. This calculator shows the percent change; the difference in points is simply the new rate minus the old one.
How do I find the price before VAT or a price rise?
Use Before the % change. A price of 121 after a 21 % increase was 100 before. For VAT specifically, the VAT calculator also shows the tax amount.
Can I use a comma as the decimal mark?
Yes. Type 12,5 or 12.5, both work. Thousands like 1.250,75 or 1,250.75 are understood too.
How do I work out a percentage of a test score?
Choose X is what % of Y and type your score and the maximum. 34 out of 40 is 85 percent.
How do I calculate a pay rise in percent?
Choose Change from X to Y and type the old and new amount. From 2500 to 2650 is a rise of 6 percent.
Does the calculator round the answer?
It shows a few decimals where needed, so you can round the way you like. Copy the number to use it elsewhere.
Something not working, or a tool you miss?