Percentage calculator
Every everyday percentage question in one place — percent of a number, percentage change, discounts, tips and bill splitting. Results update as you type.
What is X% of Y?
X is what percent of Y?
Percentage change
Increase or decrease by a percent
Discount
Tip & split
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Percentage formulas
- X% of Y:
Y × X ÷ 100. 15% of 80 = 12. - X is what % of Y:
X ÷ Y × 100. 30 is 25% of 120. - Percentage change:
(new − old) ÷ |old| × 100. From 80 to 100 is +25%. - Increase by X%:
Y × (1 + X ÷ 100). Adding 13% HST to $50 gives $56.50.
A quick mental trick
X% of Y equals Y% of X. So 8% of 50 is the same as 50% of 8, which is 4.
Comparing loan offers? The loan and mortgage calculator shows how the interest rate changes your payment.
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. 20% of 250 = 250 × 20 ÷ 100 = 50.
How do I work out a percentage increase?
Subtract the old value from the new value, divide by the old value and multiply by 100.
How do I add sales tax?
Multiply the price by 1 plus the tax rate. For 13% HST in Ontario: $50 × 1.13 = $56.50.
How do I reverse a percentage?
Divide by 1 plus the rate. A $56.50 total including 13% tax had a pre-tax price of 56.50 ÷ 1.13 = $50.