How do I calculate a percentage of a number?

Divide the percentage by 100, then multiply by the number. For example, 20% of 150 is (20 ÷ 100) × 150 = 30. Use the "What is X% of Y?" mode above to do it instantly.

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

Divide the part by the whole and multiply by 100. For example, 25 out of 200 is (25 ÷ 200) × 100 = 12.5%. Use the "X is what percent of Y?" mode.

How do I calculate percentage increase and decrease?

Subtract the old value from the new value, divide by the old value, and multiply by 100. A positive result is an increase and a negative result is a decrease. From 50 to 75 is a 50% increase; from 80 to 60 is a 25% decrease.

What is the difference between percentage and percentage points?

Percentage points measure the simple difference between two percentages, while percent change is relative. If interest rises from 4% to 6%, that is 2 percentage points but a 50% increase.

How do I calculate a discount percentage?

Subtract the sale price from the original price, divide by the original price, and multiply by 100. If a $90 item sells for $63, the discount is ((90 − 63) ÷ 90) × 100 = 30%.

How do I add or subtract a percentage from a number?

Multiply the number by (1 + percentage ÷ 100) to add, or (1 − percentage ÷ 100) to subtract. Adding 10% to 200 gives 220; subtracting 10% gives 180. Use the "Add or subtract X%" mode.

Is this percentage calculator free to use?

Yes. The calculator is completely free, runs in your browser, and requires no signup or download. Your numbers never leave your device.

Percentage Calculator

Find any percentage instantly — free, no signup.

Calculation Type

Popular percentage calculations:

Percentage (X%)

Total Value (Y)

This free percentage calculator lets you calculate the percentage of a number, find what percent one number is of another, and work out percentage increase or decrease in seconds. Pick a mode, type your numbers, and the result appears instantly with the formula and steps shown — no signup, no downloads, no limits.

How to Calculate a Percentage

Choose a calculation mode: Pick what you want to find: a percentage of a number, what percent one number is of another, the total behind a percentage, or a percentage change.
Enter your numbers: Type your values into the two fields. Decimals and negative numbers are fine.
Read the instant result: The answer updates as you type, rounded to two decimals, with the formula and your numbers substituted in so you can check the working.
Copy or reset: Use Copy result to paste the answer anywhere, or Reset to start a new calculation.

Worked example: to find 20% of 150, divide 20 by 100 to get 0.2, then multiply by 150. The answer is 30.

Percentage Calculator Formula

Percentage of a number

(Percentage ÷ 100) × Number

Example: 20% of 150 = (20 ÷ 100) × 150 = 30

What percent is X of Y

(X ÷ Y) × 100

Example: 25 of 200 = (25 ÷ 200) × 100 = 12.5%

Find the total

Part ÷ (Percentage ÷ 100)

Example: 15 is 30% of 15 ÷ 0.30 = 50

Percentage increase

((New − Old) ÷ Old) × 100

Example: From 50 to 75 = ((75 − 50) ÷ 50) × 100 = 50%

Percentage decrease

((Old − New) ÷ Old) × 100

Example: From 80 to 60 = ((80 − 60) ÷ 80) × 100 = 25%

Percentage change

((New − Old) ÷ |Old|) × 100

Example: From −40 to −20 = (20 ÷ 40) × 100 = 50% increase

Percentage Examples

Percentage	of 100	of 200	of 500
5%	5	10	25
10%	10	20	50
15%	15	30	75
20%	20	40	100
25%	25	50	125
50%	50	100	250

Common Uses of a Percentage Calculator

Discounts & Sales

Work out the sale price after a discount. Example: 30% off $80 saves you $24, so you pay $56.

Sales Tax & VAT

Add tax to a price before checkout. Example: 8% tax on $120 adds $9.60, for a total of $129.60.

Tips

Split a restaurant bill fairly. Example: an 18% tip on a $45 meal is $8.10.

Grades & Exam Marks

Convert marks into a percentage. Example: 42 out of 50 is (42 ÷ 50) × 100 = 84%.

Salary Increase

See what a raise is worth. Example: a 5% raise on $4,000 a month adds $200.

Business Profit & Margin

Check markup and margin quickly. Example: buying at $60 and selling at $90 is a 50% markup.

Interest & Loans

Estimate simple interest. Example: 6% yearly interest on $2,000 is $120 per year.

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