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Percentage calculator

Work out percentages instantly: X% of a number, percent increase or decrease, price after a discount, and what percent one number is of another, with the formula.

  • Free
  • No sign-up
  • No file uploaded
  • Windows, Mac, Android, iPhone

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About this tool

What's 15% of 240? How much did your rent go up in percent? What do you pay for a $80 jacket at 25% off? Pick the calculation, type two numbers and get the answer with the formula, so you can check the math yourself.

When to use it

Sales and coupons

See the real price of an item at 20%, 30% or 50% off and how much you save.

Percent change

Rent, salary, bills or revenue: measure how much they went up or down year over year.

Grades and scores

Turn 45 correct answers out of 60 into a percentage.

How to use

  1. Pick the calculation: X% of Y, percent change, discount, or what percent.
  2. Type the two numbers.
  3. Read the result and the formula used.
  4. Copy the result if you need it.

How it works

X% of Y: Y × X ÷ 100. Percent change: (new − old) ÷ old × 100. What percent: part ÷ total × 100.

A 20% drop followed by a 20% rise does not bring you back: 100 becomes 80, then 96.

Everything is calculated in your browser: nothing is sent to a server.

Tips for best results

  • To find the original price, divide the sale price by (1 − discount ÷ 100): $60 after 25% off was $80.
  • Percentage points are not percent: going from 10% to 12% is 2 points, but a 20% increase.
  • Two 10% discounts in a row are not 20% off, they are 19% off.
  • For sales tax or VAT, use the tax calculator, which also works backwards.

Common problems and fixes

No result appears

A field is empty or contains a letter. Type only digits, with a period for decimals.

Percent change from 0 does not work

Percent change is measured against the starting value; from zero it is infinite. Compare the amounts instead.

The result looks off by a cent

Results are rounded to two decimals; the formula shows the exact calculation.

Frequently asked questions

How do I calculate 20% of a number?

Multiply by 20 and divide by 100. 20% of 150 = 150 × 20 ÷ 100 = 30.

How do I calculate percent increase?

(new − old) ÷ old × 100. From 80 to 100 is a 25% increase.

How do I calculate a discount?

Price × (1 − discount ÷ 100). An $80 item at 25% off costs $60.

Is my data sent anywhere?

No. All calculations run in your browser.

How do I turn a score into a percentage?

Choose “What percent”: 45 out of 60 is 75%.

Related searches

Still stuck?

Ask on the forum: the category, the tool, your device sheet and the test result will be filled in for you.