What is 20 Percent of 21?
20% of 21 = 4.2
- Result
- 4.2
- Remaining
- 16.8
- 20% as decimal
- 0.2
- 21 + 20%
- 25.2
Sumwise · Checked by Theo Abbott · Data: exact arithmetic; unit definitions from NIST SP 811 · Updated · How we check it
How to work it out
- Turn the percentage into a decimal: 20 ÷ 100 = 0.2
- Multiply: 0.2 × 21 = 4.2
- Check: Work backwards: 4.2 ÷ 21 × 100 = 20%.
Another method. As a proportion of part to whole: 20/100 = part/21, so part = 20 × 21 ÷ 100 = 4.2. Both methods always give the same answer.
In a spreadsheet: =20%*21. Forgetting to divide the percentage by 100 makes the answer 100 times too big. Note that x% of y always equals y% of x.
What the result means
4.2 is the 20% share of 21. The remaining 80% is 16.8, and the two parts add back up to 21.
Discounts: 20% off an item priced $21 saves $4.2, so you pay $16.8.
Adding and taking away 20%
Increasing 21 by 20% gives 25.2 and decreasing it by 20% gives 16.8. These do not cancel out: raising 21 by 20% and then lowering the result by 20% ends at 20.16, because the second 20% is taken of a bigger number.
Related results
| 5% of 21 | 5% of 21 = 1.05 |
| 10% of 21 | 10% of 21 = 2.1 |
| 15% of 21 | 15% of 21 = 3.15 |
| 25% of 21 | 25% of 21 = 5.25 |
| 50% of 21 | 50% of 21 = 10.5 |
| 75% of 21 | 75% of 21 = 15.75 |
The other way round: 21% of 20
Practice
| 4% of 8 | Show answer4% of 8 = 0.32 |
| 38% of 60 | Show answer38% of 60 = 22.8 |
| 77% of 94 | Show answer77% of 94 = 72.38 |
| 46% of 31 | Show answer46% of 31 = 14.26 |
| 4% of 97 | Show answer4% of 97 = 3.88 |
| 14% of 48 | Show answer14% of 48 = 6.72 |
How answers are calculated and checked: methodology.
Questions
What is 20 Percent of 21?
20% of 21 is 4.2. Formula, steps and practice examples.
What is 20% off 21?
16.8. Taking 20% off leaves 80% of 21.
What is 21 plus 20%?
25.2. Adding 20% is the same as multiplying by 1.2.