The answer is 20. Below: three ways to calculate it, a mental shortcut, and the real-world contexts where this percentage shows up.
20% of 100 is 20.
A 20% discount is one of the most common sales tags — and 100 is the easiest base to learn the trick.
Divide the percent by 100 to convert it: 20 ÷ 100 = 0.2.
Multiply: 100 × 0.2 = 20.
20% means 20/100. So 20% of 100 is (20 × 100) ÷ 100.
Compute: 20 × 100 = 2000, then divide: 2000 ÷ 100 = 20.
For 20%, find 10% first (decimal one place left), then double it. 10% of 100 is 10; double that is 20.
A discount is just a percentage subtracted from the original price. To find the final price, calculate the discount first, then subtract.
A 20% off sticker on a $100 item means you save $20 and pay $80 at checkout.
If you only needed to look up this one number, here are some related ones using the same base of 100:
| Calculation | Answer |
|---|---|
| 10% of 100 | 10 |
| 25% of 100 | 25 |
| 30% of 100 | 30 |
| 50% of 100 | 50 |
| Calculation | Answer |
|---|---|
| 20% of 10 | 2 |
| 20% of 20 | 4 |
| 20% of 25 | 5 |
| 20% of 30 | 6 |
| 20% of 50 | 10 |
For any percentage of any number, use our percentage of a number calculator.
Multiply 100 by 0.2 (the decimal form of 20%). Or equivalently, multiply by 20/100. The result is 20.
Divide 20 by 100 and multiply by 100. That is exactly 20% — confirming the original calculation.
You save 20 and pay 80 at checkout.