Solve everyday percentage questions. This free percentage calculator finds a percent of a number, works out what percent one number is of another, and calculates percentage increase or decrease, with the working shown.
Calculate
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Find a percentage of a number — for example, what is 15% of 200?
Find what percentage one number is of another — for example, 30 is what % of 200?
Find the percentage increase or decrease from one value to another — for example, from 200 to 250.
Result
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Enter your numbers
Working
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Also
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As decimal
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Percent means “per hundred.” To find a percentage of a number, multiply by the percent and divide by 100. To express one number as a percentage of another, divide and multiply by 100.
Use this free percentage calculator to find a percentage of a number, work out what percent one number is of another, or calculate a percentage increase or decrease.
What this percentage calculator does
This percentage calculator handles the three most common questions: what is X% of Y, X is what percent of Y, and the percentage change from one value to another — each with the working shown.
Percentage formulas
% of a number: result = number × percent ÷ 100
X is what % of Y: percent = X ÷ Y × 100
% change: change = (new − old) ÷ old × 100
So 15% of 200 = 30, 30 is 15% of 200, and going from 200 to 250 is a 25% increase.
Worked examples
Question
Answer
20% of 150
30
45 is what % of 90
50%
From 80 to 100
+25%
From 100 to 80
−20%
Percentage increase vs decrease
A jump from 100 to 125 is a 25% increase, but going back from 125 to 100 is only a 20% decrease — because the starting number is different each time. The calculator always divides by the original value.
How to use the percentage calculator
Pick a mode — % of a number, X is what %, or % change.
Enter the two numbers.
Read the result with its working.
Percentage FAQ
How do I find a percentage of a number?
Multiply the number by the percent and divide by 100. For example, 15% of 200 is 200 × 15 ÷ 100 = 30.
How do I work out what percent one number is of another?
Divide the first number by the second and multiply by 100. So 30 ÷ 200 × 100 = 15%.
How do I calculate percentage change?
Subtract the old value from the new, divide by the old value, then multiply by 100. From 200 to 250 is (250 − 200) ÷ 200 × 100 = 25%.
Why isn't a 25% rise cancelled by a 25% fall?
Because each percentage is taken from a different starting number. A 25% rise from 100 gives 125, but a 25% fall from 125 gives about 94 — you'd need only a 20% fall to return to 100.
How do I add or subtract a percentage?
To add 15%, multiply by 1.15; to subtract 15%, multiply by 0.85. So 200 + 15% is 230 and 200 − 15% is 170.
Is the percentage calculator free?
Yes, this percentage calculator is completely free, needs no sign-up, and gives instant results in your browser.
