Percentage Calculator
Work out what X% of a number is, and add or subtract a percentage instantly.
About this tool
A percentage calculator turns a percentage and a number into a clear answer. Enter a percentage and an amount, and this tool instantly shows what that percentage of the amount is, along with the amount after the percentage is added and after it is subtracted. It is the fastest way to compute discounts, tips, tax, commissions, markups and any everyday percentage.
The core math is simple: a percentage is just a fraction of 100, so X% of Y is (X ÷ 100) × Y. To add a percentage you multiply the amount by (1 + X ÷ 100); to subtract one — for a sale price or a discount — you multiply by (1 − X ÷ 100). This calculator runs all three at once so you can read the result, the increased total and the reduced total side by side.
Use it to find a 15% tip on a restaurant bill, a 20% discount on a price, sales tax on a purchase, or a percentage raise on a salary. Adjust either field to see the numbers update live. Everything is calculated locally in your browser — no figures are uploaded, logged or stored anywhere.
Examples
Input
15% of 200
Output
30 (200 + 15% = 230, 200 − 15% = 170)
The added total is handy for tax or tips; the subtracted total gives a sale price.
Input
20% of 1,500
Output
300 (1,500 + 20% = 1,800, 1,500 − 20% = 1,200)
Input
7.5% of 80
Output
6 (80 + 7.5% = 86, 80 − 7.5% = 74)
Common uses
- Calculating a 15% tip on a restaurant bill before splitting it
- Finding the sale price after a 20% discount while shopping
- Working out sales tax to add onto a purchase total
- Checking a percentage raise on a salary or hourly rate
- Computing a commission or markup on a quoted amount
Frequently asked questions
How do I calculate X% of Y?
Multiply the two and divide by 100: X% of Y is (X ÷ 100) × Y. For example, 15% of 200 is (15 ÷ 100) × 200 = 30. This calculator does it automatically as you type.
How do I add a percentage to a number?
Multiply the number by (1 + percentage ÷ 100). To add 15% to 200, compute 200 × 1.15 = 230. The 'Amount + %' result shows this for you.
How do I subtract a percentage from a number?
Multiply the number by (1 − percentage ÷ 100). To take 15% off 200, compute 200 × 0.85 = 170. The 'Amount − %' result shows this — handy for sale prices and discounts.
Is this percentage calculator free?
Yes. It is completely free to use with no sign-up, no limits and no hidden charges.
Are my numbers private?
Yes. Every calculation runs locally in your browser. The values you enter are never sent to a server, logged or stored.
Embed this tool
Free to use on your own site. It stays fast and private for your visitors.
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