Percentage Calculator

Work out any everyday percentage: what X% of a number is, what percent one number is of another, and the percent increase or decrease between two values, with every step shown. Everything runs in the browser.

X% of Y
X is what % of Y
Percent change
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A percentage is a number out of 100. To find X% of Y, multiply Y by X ÷ 100. To find what percent X is of Y, divide X by Y and multiply by 100. To find the percent change from X to Y, divide the difference (Y − X) by the starting value X and multiply by 100. A positive result is an increase and a negative result is a decrease.

Examples: 20% of 150 is 30. 30 is 20% of 150. Going from 50 to 75 is a 50% increase, and going from 80 to 60 is a 25% decrease. People also search this as a percent calculator, a percentage increase calculator, or a percent change calculator; they all live on this one page.

Shopping for a sale price instead? The percent off calculator finds the discount and final price from an original price. Simplify a ratio or see it as a percentage with the ratio calculator, solve A / B = C / D with the proportion calculator, find the greatest common factor with the GCF calculator, break a number into primes with the factoring calculator, find the slope between two points with the slope calculator, or measure the spread of a data set with the standard deviation calculator. Browse more tools in the Math hub.

How to use the percentage calculator

Pick a calculation: X% of Y, X is what percent of Y, or percent change from X to Y.
Enter the two numbers. Decimals, negatives, commas, and a trailing % sign are fine.
Read the answer in the result panel; it updates as you type.
Follow the step-by-step work to see how the answer was found.

Frequently asked questions

How do I calculate a percentage of a number?

Divide the percent by 100 to turn it into a decimal, then multiply by the number. For example, 20% of 150 is 0.20 × 150 = 30. Pick the "What is X% of Y?" mode, enter 20 and 150, and the calculator shows the answer and each step.

How do I find what percent one number is of another?

Divide the part by the whole and multiply by 100. For example, 30 out of 150 is 30 ÷ 150 = 0.2, and 0.2 × 100 = 20%. Use the "X is what % of Y?" mode for this.

How do I calculate percent change?

Subtract the starting value from the new value, divide by the starting value, and multiply by 100. Going from 50 to 75 is (75 − 50) ÷ 50 × 100 = a 50% increase. Going from 80 to 60 is (60 − 80) ÷ 80 × 100 = −25%, a 25% decrease.

What is the percentage formula?

The core formula is Part = Percent ÷ 100 × Whole. Rearrange it to find any missing piece: Percent = Part ÷ Whole × 100, and Whole = Part ÷ (Percent ÷ 100). Percent change uses (New − Old) ÷ |Old| × 100.

What is the difference between percent change and percentage points?

Percent change is relative to the starting value, while percentage points are a simple subtraction of two percentages. A rate that goes from 10% to 15% rose 5 percentage points, but that is a 50% increase in the rate itself.

Why isn't a 50% increase followed by a 50% decrease back to the start?

Each percent is applied to a different base. 100 increased by 50% is 150, but 50% of 150 is 75, so a 50% decrease lands at 75. To undo a 50% increase you need a 33.33% decrease.

Can a percentage be more than 100% or negative?

Yes. A part bigger than the whole gives more than 100% (150 is 150% of 100), and a value that more than doubles shows a percent increase over 100%. A negative percent change means the value went down. Percent change from a starting value of 0 is undefined.

Is this the same as a percent off or discount calculator?

No. This is a general percentage calculator for percents of numbers, part-to-whole percentages, and percent change. To find a sale price after a discount, use the percent off calculator, which handles original price, percent off, and dollars off.