Ups and downs are not symmetric
A 50% fall needs a 100% rise to get back to the start.
Percentage Calculator
Every everyday percentage question in one place: what is 15% of a price, what percent one number is of another, how much something went up, or what your exam marks are as a percentage.
- 100% free
- No sign-up
- Runs in your browser
What is X% of Y?
% of
X is what percent of Y?
is what % of
Percentage change from X to Y
From to
Increase or decrease by a percentage
%
Percentage difference between two values
and
Marks to percentage
out of
How to use
How to use the Percentage Calculator
- Find the calculator that matches your question.
- Type your numbers into it.
- Read the answer straight away; all six update as you type.
Private by design. Calculations happen in your browser. Nothing you enter is uploaded or stored.
About this tool
The percentage formulas behind each calculator
X% of Y is X ÷ 100 × Y. "X is what percent of Y" is X ÷ Y × 100. Percentage change from an old value to a new one is (new − old) ÷ old × 100, which is why going from 80 to 100 is a 25% increase, but going back from 100 to 80 is only a 20% decrease.
Percentage difference is used when neither value is the "original": it divides the gap by the average of the two. Marks to percentage is simply marks obtained divided by total marks, times 100.
Good to know
Percentage pitfalls
Points vs percent
A rate rising from 10% to 12% is 2 percentage points, but a 20% increase.
Check the base
Always ask "percent of what?" before comparing figures.
Stacked changes
Two 10% increases add up to 21%, not 20%.
FAQ
Percentage Calculator FAQs
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 15% of 2,500 is 375.
How do I calculate percentage increase?
Subtract the old value from the new value, divide by the old value and multiply by 100.
How do I convert marks to a percentage?
Divide marks obtained by total marks and multiply by 100. 935 out of 1,100 is 85%.
What is the difference between percentage change and percentage difference?
Change compares a new value with an original one. Difference compares two values with no original, using their average.
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