Percentage Calculator
Percent of a number, change, discounts
150 × 20 ÷ 100 = 30
30 ÷ 150 × 100 = 20
30 × 100 ÷ 20 = 150
(100 − 80) ÷ 80 × 100 = 25
200 × (1 + 15 ÷ 100) = 230
120 ÷ (1 + 20 ÷ 100) = 100
Formula: part = whole × percent ÷ 100 · Updated Oct 22, 2026
Six percentage questions on one page. Type two numbers in any box and the answer appears at once, with the calculation written out underneath.
All percentage calculators
PercentagesPercent of a number, change, discounts
Prices & taxVAT, sales tax, margin and markup
Everyday mathsAverages and the rule of three
How to use the Percentage Calculator
- Pick the question that matches yours: what is P% of a number, A is what percent of B, A is P% of what, or add / subtract a percentage.
- Type the two numbers you know. Decimals and negative numbers work, and you can type the % sign.
- Read the answer and the worked formula under it. Copy puts all answers on your clipboard.
Percentage formulas
- P% of a number: number × P ÷ 100. 20% of 150 = 150 × 20 ÷ 100 = 30.
- A is what percent of B: A ÷ B × 100. 30 is 20% of 150.
- A is P% of what: A × 100 ÷ P. 30 is 20% of 150.
- Add P%: number × (1 + P ÷ 100). Subtract P%: number × (1 − P ÷ 100).
Common percentages of 200
| Percent | Of 200 | Of 1,000 |
|---|---|---|
| 1% | 2 | 10 |
| 5% | 10 | 50 |
| 10% | 20 | 100 |
| 12.5% | 25 | 125 |
| 15% | 30 | 150 |
| 20% | 40 | 200 |
| 25% | 50 | 250 |
| 30% | 60 | 300 |
| 33% | 66 | 330 |
| 40% | 80 | 400 |
| 50% | 100 | 500 |
| 75% | 150 | 750 |
Percent of a percent
Percentages of percentages multiply: 50% of 20% is 10%, not 30%. A 20% discount followed by another 10% is 28% off in total — the discount calculator does this for you.
Related guides
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. 15% of 80 = 80 × 15 ÷ 100 = 12.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. 45 out of 60 = 45 ÷ 60 × 100 = 75%.
How do I reverse a percentage?
If 30 is 20% of a number, the number is 30 × 100 ÷ 20 = 150. Use the third box.
Can the result be over 100%?
Yes. 50 is 125% of 40 — the part is bigger than the whole.
More calculators
Results are rounded for display; the calculation itself uses full precision. Tax and price results are estimates — check the official rate for your case.