Percentage calculator
Four percentage calculations in one place: a percent of a number, what percent one number is of another, the change between two numbers, and adding or taking off a percent.
- 100% free
- Runs in your browser
- No uploads
Result
Fill in both numbers to see the answer.
- Runs on your deviceEvery tool works directly in your browser. No files are uploaded.
- Your privacy mattersYour files never leave your device, so there's nothing for us to store.
- No limitsUse any tool as much as you need. No daily caps, no waiting.
- Completely freeNo signup and no trial to cancel. Ads keep the tools free.
How to use the percentage calculator
- Pick a calculation. Choose % of, What %, % change or +/− % at the top of the calculator.
- Type two numbers. You can use commas and decimals, like 1,250.50. The answer updates as you type.
- Read or copy the result. The calculator shows the answer, a sentence explaining it, and the formula it used.
Percentage formulas
| Question | Formula | Example |
|---|---|---|
| What is P% of X? | P ÷ 100 × X | 15% of 60 = 9 |
| A is what % of B? | A ÷ B × 100 | 9 is 15% of 60 |
| % change from A to B | (B − A) ÷ |A| × 100 | 60 to 75 = +25% |
| X increased by P% | X × (1 + P ÷ 100) | 60 + 25% = 75 |
| X decreased by P% | X × (1 − P ÷ 100) | 75 − 20% = 60 |
Everyday examples
Shopping. A $80 jacket with 25% off: 25% of 80 is 20, so you pay $60. With 8% sales tax on top, $60 increased by 8% is $64.80.
Pay rise. Your hourly pay goes from $18 to $19.80. The % change mode shows a 10% raise.
Test scores. 42 correct out of 50 questions: 42 is 84% of 50.
Tips. 18% of a $46 bill is $8.28. The Tip calculator can also split it between people.
Common percentage mistakes
Using the wrong starting point. A change is always measured against the starting value. A drop from 50 to 40 is a 20% decrease, but the rise from 40 back to 50 is 25%.
Adding percentages together. Two discounts of 10% and 20% don't make 30% off. Applied one after the other they make 28% off, because the second discount is taken from the already reduced price.
Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number. For 20% of 150: 20 ÷ 100 = 0.2, and 0.2 × 150 = 30.
How do I work out a percentage increase?
Subtract the old value from the new one, divide by the old value, then multiply by 100. Going from 80 to 100: (100 − 80) ÷ 80 × 100 = 25% increase.
Is a 20% increase followed by a 20% decrease back where I started?
No. 100 increased by 20% is 120, but 120 decreased by 20% is 96. The second percentage is taken from a bigger number, so it removes more than the first one added.
What's the difference between percent and percentage points?
If an interest rate goes from 4% to 5%, it rose by 1 percentage point, but by 25 percent (because 1 is a quarter of 4). Percentage points compare two percentages directly; percent describes the relative change.
How do I take a percentage off a price?
Use the +/− % mode and enter a negative number, such as −15 for 15% off. Or multiply the price by (1 − 0.15). The Discount calculator also shows how much you save.