Percentage Calculator
Nine calculators in one: percentages, increases and decreases, discounts, tips and more. Pick a mode and get your answer as you type.
Find what a given percentage of a number equals — e.g. how much 15% of 200 is.
Work out what percentage one number represents of another — e.g. 30 out of 200.
Add a percentage on top of a number — e.g. a price after a 20% increase.
Take a percentage off a number — e.g. a price after a 20% decrease.
Find the percentage change between two numbers, with the direction shown automatically.
Work backwards from a result to find the original number — e.g. a price after tax is added.
See the final price and amount saved for a single discount.
Discounts applied one after another, not added together — e.g. 10% off, then a further 5% off.
Work out the tip, the total bill, and how much each person owes.
How to calculate a percentage
A percentage is just a fraction out of 100. To find what a percentage of a number is, divide the percentage by 100 and multiply by the number — 15% of 200 is (15 ÷ 100) × 200 = 30. To find what percentage one number is of another, divide the part by the whole and multiply by 100.
Percentage increase and decrease
To increase a number by a percentage, multiply it by 1 plus the percentage as a decimal. To decrease it, multiply by 1 minus the percentage as a decimal. Percentage change between two numbers is the difference divided by the original number, multiplied by 100 — a positive result is an increase, a negative result is a decrease.
Reverse percentages and discounts
Reverse percentage problems start from the result and work backwards to the original number, which is useful for figures that already include tax or a markup. Stacked discounts are different from adding percentages together: two discounts of 10% do not equal 20% off, because the second discount applies to the already-reduced price.
Frequently asked questions
Is 10% off twice the same as 20% off?
No. Two 10% discounts applied one after another come to 19% off the original price, not 20%, because the second discount is calculated on the already-discounted price. Use the stacked discounts mode above to see the exact figure for any combination.
How do I find the original price before a discount or tax?
Use the reverse percentage mode with the final amount and the percentage that was added or removed. It divides the final number back out to give you the original figure.
Why is percentage change different from percentage of?
Percentage of a number is a share of that number. Percentage change compares two different numbers to each other and always measures the difference against the original (starting) value, not the new one.