Percentage Calculator
Four essential calculations. Results update instantly as you type.
What is X% of Y?
Calculate a percentage of any number. Useful for tips, discounts, and tax.
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Result
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X is what percent of Y?
Find what percentage one number is of another. Useful for completion rates.
Percentage
0%
Percentage Change
Calculate the increase or decrease between two values. Useful for tracking growth.
Change
0%
Add or Subtract a Percentage
Increase or decrease a number by a percentage. Useful for markups and discounts.
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Result
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Quick Reference Formulas
X% of Y
(X ÷ 100) × Y
X is ?% of Y
(X ÷ Y) × 100
% Change
((New − Old) ÷ Old) × 100
Add/Sub %
X × (1 ± P÷100)
Common Questions
To find the original number before a percentage was added, divide by (1 + percentage/100). For example, if £120 includes 20%, the original was £120 ÷ 1.20 = £100.
Percentage points measure the absolute difference between two percentages. If interest rates go from 2% to 3%, that's 1 percentage point but a 50% relative increase.
Profit margin = ((Revenue − Cost) ÷ Revenue) × 100. If you sell for £100 what cost £60, your margin is ((100 − 60) ÷ 100) × 100 = 40%.