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Percentage Calculator

Calculate percentages, percent change, reverse percentages, and percentage add-ons or discounts.

Percentage inputs

Result

15% of 200 is 30
Formula
(15 / 100) x 200 = 30

How to use this percentage calculator

Use this calculator for quick percentage questions without setting up a spreadsheet.

  1. Choose the calculation type that matches your question.
  2. Enter the two numbers requested by the labels.
  3. Use the result panel to check the answer sentence and formula.
  4. Switch calculation types to reuse the same numbers in another percentage question.

Common percentage calculations

This calculator handles everyday percentage questions: finding a percent of a number, finding what percent one value is of another, calculating percent increase or decrease, and adding or subtracting a percentage from a starting value.

  • What is X% of Y? Use this percent of a number equation to calculate results like 15% of 200.
  • X is what percent of Y? Use this percentage of total equation to find the percent one number represents out of another.
  • Percentage increase or decrease. Use this percent change equation to compare an original value with a new value.
  • Add or subtract a percentage. Use this percentage adjustment equation for discounts, markups, tips, tax, and other increases or decreases.
  • Original value before percentage change. Use this reverse percentage equation to find the starting value before an increase, decrease, discount, or markup.

Percent means “per 100.” For example, 15% is the same as 15 out of 100, or 0.15 as a decimal.

Percentage formulas

Percent of a number
R = \frac{P}{100} \times N

P is the percentage, N is the number, and R is the result.

Percent change
\Delta\% = \frac{New - Original}{Original} \times 100

A positive result is an increase. A negative result is a decrease.

Original value before percentage change
Original = \frac{Final}{1 \pm \frac{P}{100}}

Use plus for a final value after an increase and minus for a final value after a decrease or discount.

Percentage calculator FAQ

How do I calculate a discount?
Choose add or subtract a percentage, enter the original price as the starting value, enter the discount percentage, and choose subtract percentage.
How do I calculate a percentage increase?
Choose percentage increase or decrease, enter the original value, then enter the new value. A positive result means the value increased.
What does reverse percentage mean?
Reverse percentage can mean finding the original value before a percentage increase or decrease. Choose Original value before percentage change for that calculation. If you need to find what percent one number is of another, choose X is what percent of Y.
Can percentages be over 100?
Yes. A percentage over 100 means the value is larger than the comparison value or more than the whole amount.

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