How to find 80 percent of 100
"Percent" means per hundred, so 80% is the fraction 80/100, or 0.8 as a decimal. Taking 80 percent of 100 means multiplying 100 by that fraction:
80% of 100 = 100 x 80 / 100
= 8,000 / 100
= 80The same answer comes from the decimal form: 100 x 0.8 = 80. And because multiplication is commutative, 80% of 100 equals 100% of 80, which is sometimes the easier way to see it in your head.
Mental math shortcut
10% of 100 is 10 (move the decimal one place left), and 1% is 1. Build 80% from those pieces: 8 x 10 = 80.
Nearby percentages of 100
| Percent | Of 100 | 100 minus it | 100 plus it |
|---|---|---|---|
| 1% | 1 | 99 | 101 |
| 5% | 5 | 95 | 105 |
| 10% | 10 | 90 | 110 |
| 15% | 15 | 85 | 115 |
| 20% | 20 | 80 | 120 |
| 25% | 25 | 75 | 125 |
| 30% | 30 | 70 | 130 |
| 50% | 50 | 50 | 150 |
| 75% | 75 | 25 | 175 |
| 79% | 79 | 21 | 179 |
| 81% | 81 | 19 | 181 |
| 85% | 85 | 15 | 185 |
80 percent of other amounts
| Amount | 80% of it |
|---|---|
| 20 | 16 |
| 25 | 20 |
| 30 | 24 |
| 40 | 32 |
| 50 | 40 |
| 60 | 48 |
| 75 | 60 |
| 80 | 64 |
| 120 | 96 |
| 150 | 120 |
Where this comes up
A 80% discount on a 100 price takes off 80, leaving 20. A 80% tip or tax on 100 adds 80, for a total of 180. If 100 is a score out of a possible total, 80% of it is the share 80 represents. For percent change, reverse percentages, and "X is what percent of Y", use the full percentage calculator.