How is percent change calculated?

((new − old) / old) × 100, with sign indicating increase or decrease.

Reverse percentage example?

If 80 is the value after a 20% discount, the original value is 100.

Can I chain discounts?

Apply one discount at a time; multiple discounts must be calculated in order.

Percentage Calculator

Calculate a percentage of a number, percentage increases and decreases, percentage change, or an original value before a discount.

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About this tool

Solve common percentage calculations, including finding a percentage of a number, increasing or decreasing a value, comparing the percentage change between two values, and finding an original amount from a discounted result.

How to use

Find a percentage of a number
Increase or decrease a number by a percentage
Calculate percentage change
Find the original value before a discount
Show the formula used
Select problem type: Choose of, change, increase, decrease, or reverse.
Enter values: Fill in percentages and amounts.
Read answer: Copy numeric result and verify formula.

Examples

Calculate sales tax
Compare a value with the previous month
Find the original price before a discount
Calculate a restaurant tip

Limitations

Money results may need to be rounded to the required number of decimal places
Multiple successive percentage changes must be calculated in order
The entered values and calculations are processed directly in your browser and are not sent to a server.

FAQ

How is percent change calculated?: ((new − old) / old) × 100, with sign indicating increase or decrease.
Reverse percentage example?: If 80 is the value after a 20% discount, the original value is 100.
Can I chain discounts?: Apply one discount at a time; multiple discounts must be calculated in order.