Free Percentage Calculator
Calculate percentages instantly with our free online percentage calculator. Find a percentage of a number, calculate percentage increases and decreases, and discover original values with simple step-by-step solutions.
Percentage Calculator
Calculate a percentage of a number, find what percent one number is of another, measure a change, or recover an original value.
Result
Popular calculators
Each tool uses the same careful math as the calculator above, with a layout that focuses on one kind of problem at a time.
Percentage Increase
Find how much a value has grown, with the difference and the formula shown.
Open tool →Percentage Decrease
Measure a drop in price, quantity, or score without mixing it up with an increase.
Open tool →Reverse Percentage
Work backwards from a part, a discounted price, or a value after an increase.
Open tool →Fraction to Percentage
Convert a fraction or exam mark, such as 42 out of 50, into a clear percentage.
Open tool →Discount Calculator
Turn an original price and a discount into the amount saved and the final price.
Open tool →Percentage Difference
Compare two values using their midpoint, and see how that differs from a change.
Open tool →Percentage Change
Handle increases and decreases in one place, including a change down to zero.
Open tool →Profit Percentage
Find profit or loss as a percentage of cost price, with the amount shown too.
Open tool →More tools for school, pay, and shopping
These calculators use the same formulas, with U.S. examples and the working shown.
Grade Percentage
Turn points earned and points possible into a test percentage.
Open tool →Raise Calculator
New pay after a percent increase, in dollars.
Open tool →Sales Tax
Add a sales tax rate you enter to a pre-tax price.
Open tool →Markup Calculator
Profit as a percent of cost, or a price from a markup.
Open tool →Tip Split
Tip a bill and split the total evenly.
Open tool →Attendance Percentage
Days attended, and how many more you need for a target.
Open tool →See every calculator on the percentage tools page. The earlier All Free Tools address is unchanged.
Calculator categories
Basic percentage
What is X% of Y, and what percent one number is of another.
Open tool →Percentage change
Increases, decreases, and signed change between two values.
Open tool →Reverse percentage
Recover the original number after a part, a discount, or an increase.
Open tool →Shopping and discounts
Sale prices, percentage off, and original prices before a markdown.
Open tool →Education
Marks, fractions, and exam scores as percentages.
Open tool →Business calculations
Profit percentage and related money calculations.
Open tool →How percentage calculations work
A percentage is a way of writing a number as a part of 100. If 15 out of every 100 parts of something are selected, that is 15%.
To convert a fraction or a ratio into a percentage, divide the part by the whole and multiply by 100. To take a percentage of a number, convert the percentage to a decimal (divide by 100) and multiply.
Two comparisons are easy to mix up. Percentage change uses one starting value as the base: ((new − original) ÷ original) × 100. Percentage difference uses the midpoint of the two values as the base, so the result is the same whichever value you enter first. This site keeps those formulas on separate tools so the reference value stays clear.
Calculations run in your browser. The numbers you type are not sent to our server to be computed. Results that would be undefined — for example a percentage change from an original value of 0 — are explained with an error message instead of showing Infinity or NaN. Rounding is only applied to the displayed figure, typically up to six decimal places, and is trimmed of trailing zeros.
For a fuller account of the formulas and edge cases, see our calculation methodology.
Popular examples
Convert 15% to 0.15, then multiply: 0.15 × 200 = 30.
Divide 30 by 200 to get 0.15, then multiply by 100. The answer is 15%.
The difference is 45. 45 ÷ 150 × 100 = 30%, so this is a 30% increase.
The remaining fraction is 0.80. Original price = 80 ÷ 0.80 = 100.
Educational guides
If you want to work through percentages on a hand calculator as well as on this site, start with this guide:
Frequently asked questions
How do you calculate a percentage?
Divide the part by the whole and multiply by 100. If you scored 45 out of 60, the percentage is (45 ÷ 60) × 100 = 75%. The calculator on this page shows that working as you type.
How do you calculate percentage increase?
Use ((new value − original value) ÷ original value) × 100. If sales grew from $200 to $250, the increase is 25%. Use the Percentage change tab, or the dedicated increase calculator, for a live result.
How do you find what percentage one number is of another?
Divide the first number by the second and multiply by 100. For example, 30 is 25% of 120 because 30 ÷ 120 × 100 = 25.
How do you calculate percentage decrease?
Use ((original value − new value) ÷ original value) × 100. A price drop from $100 to $85 is a 15% decrease.
How do you solve reverse percentage problems?
If you know a part and the percentage it represents, divide the part by the percentage as a decimal. If 40 is 25% of some number, 40 ÷ 0.25 = 160. If you know a price after a discount, divide by (1 − discount ÷ 100). A 100% reduction cannot be reversed, because the remaining amount would be 0 for any original value.
Is this calculator free, and do I need an account?
Yes, it is free to use in your browser, and you do not need to create an account. Advertising may appear on the page; it is separate from the calculator itself.