How to find 40 percent of 100
"Percent" means per hundred, so 40% is the fraction 40/100, or 0.4 as a decimal. Taking 40 percent of 100 means multiplying 100 by that fraction:
40% of 100 = 100 x 40 / 100
= 4,000 / 100
= 40The same answer comes from the decimal form: 100 x 0.4 = 40. And because multiplication is commutative, 40% of 100 equals 100% of 40, 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 40% from those pieces: 4 x 10 = 40.
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 |
| 35% | 35 | 65 | 135 |
| 39% | 39 | 61 | 139 |
| 41% | 41 | 59 | 141 |
| 45% | 45 | 55 | 145 |
| 50% | 50 | 50 | 150 |
40 percent of other amounts
| Amount | 40% of it |
|---|---|
| 20 | 8 |
| 25 | 10 |
| 30 | 12 |
| 40 | 16 |
| 50 | 20 |
| 60 | 24 |
| 75 | 30 |
| 80 | 32 |
| 120 | 48 |
| 150 | 60 |
Where this comes up
A 40% discount on a 100 price takes off 40, leaving 60. A 40% tip or tax on 100 adds 40, for a total of 140. If 100 is a score out of a possible total, 40% of it is the share 40 represents. For percent change, reverse percentages, and "X is what percent of Y", use the full percentage calculator.