Percentage Calculator
Calculate percentages quickly — find X% of Y, percentage change, and reverse percentages.
Result
20% of 150 is
30
In-depth explanation
Percentages express a number as a fraction of 100. Use this tool to find a percentage of a value, work out percentage increase or decrease, or reverse a percentage to find the original amount. Everything runs locally in your browser — your inputs are not uploaded to produce the result.
Multiply the number by the percentage, then divide by 100. For example, 20% of 150 is (150 × 20) ÷ 100 = 30. Subtract the original from the new value, divide by the original, then multiply by 100. A rise from 80 to 100 is a 25% increase.
A reverse percentage finds the original value before a percentage was applied. If a price is £120 after a 20% increase, the original was £100. Tweak the inputs above to compare options, then copy or note the result you need.
Frequently asked questions
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