How to use Percentage Calculator
- Pick the calculation you need.
- Enter your numbers.
- Read the answer instantly.
Percentage formulas
X% of Y = Y × X ÷ 100. X is what % of Y = X ÷ Y × 100. Percentage change from A to B = (B − A) ÷ A × 100.
Everyday uses
Shop discounts, tips, exam scores, tax, salary raises, price changes and investment returns all use these three formulas.
Worked examples
Discount: 25% off a 1,200 price is 300, so you pay 900. Exam score: 72 marks out of 90 is 80%. Salary raise: going from 50,000 to 56,000 is a 12% increase. Price drop: from 80 to 60 is a 25% decrease.
Percent change vs percentage points
If an interest rate rises from 4% to 5%, that is 1 percentage point, but a 25% increase. Mixing these up is one of the most common mistakes in news and finance.
Reverse percentages
If a price after 20% tax is 120, the original is 120 ÷ 1.20 = 100 — not 120 minus 20%. Similarly, a price of 80 after a 20% discount was originally 80 ÷ 0.80 = 100.
Frequently asked questions
How do I add a percentage to a number?
Multiply by (1 + percent ÷ 100). Adding 18% to 500 gives 500 × 1.18 = 590.
How do I calculate a tip?
Use “X% of Y”. A 15% tip on a bill of 60 is 9.
How do I calculate a discount?
Use “X% of Y” to find the discount amount, then subtract it from the price. A 20% discount on 50 is 10, so you pay 40.
Is this tool really free?
Yes. It is 100% free with no sign-up, no watermark and no limit on how many times you use it.
Last updated: · Free to use, no sign-up.