Calculate any percentage in seconds.
Seven calculators in one: percent of a number, percentage change, add or subtract a percentage, reverse a discount or tax, and more, each with the working shown.
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Percentage of a number
Find a part of a whole, like a discount or tip.
What is % of ?
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One number as a percentage of another
What share is one value of the total?
is what % of ?
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Find the whole from a part
You know the part and its percentage, find the total.
is % of what number?
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Percentage increase or decrease
How much did a value grow or shrink?
From to
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Add or subtract a percentage
Add VAT or tax, or take off a discount.
by %
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Work back to the original value
Remove a tax or discount to find the starting price.
is after a %
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Percentage difference
Compare two values when neither is the “original”.
Between and
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The formulas
Percent of a number
result = percent ÷ 100 × number
20% of 150 = 20 ÷ 100 × 150 = 30
Percentage change
(new − old) ÷ |old| × 100
From 200 to 250: (250 − 200) ÷ 200 × 100 = 25%
Add or subtract a percent
number × (1 ± percent ÷ 100)
80 plus 15% = 80 × 1.15 = 92
Percentage difference
|a − b| ÷ ((a + b) ÷ 2) × 100
Between 80 and 120: 40 ÷ 100 × 100 = 40%
Questions people ask
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number. For example 20% of 150 is 20 ÷ 100 × 150 = 30. The first calculator does this for you and shows the working.
What is the difference between percentage change and percentage difference?
Percentage change compares a new value with an old one, so the order matters: 200 to 250 is +25%, but 250 to 200 is −20%. Percentage difference compares two values with no “before” and “after”, so it uses their average as the base and gives the same answer either way.
How do I add VAT, tax or a tip to a price?
Use “Add or subtract a percentage”. Choose Increase, enter the price and the rate. To remove tax from a price that already includes it, use “Work back to the original value”.
Why is a 50% increase followed by a 50% decrease not back to the start?
Because the second percentage applies to a bigger number. 100 plus 50% is 150, and 50% of 150 is 75, so you land on 50, not 100. To undo a 50% increase you need a 33.3% decrease.
Can I type numbers with commas or negative values?
Yes. Commas and spaces are ignored, so 1,250.50 works, and negative numbers work where they make sense. Use a dot as the decimal separator.
Are my numbers saved or sent anywhere?
No. Everything is calculated in your browser and nothing is stored or uploaded.