What is 5 Percent of 21?
5% of 21 = 1.05
Step by step
- Turn the percentage into a decimal: 5 ÷ 100 = 0.05
- Multiply: 0.05 × 21 = 1.05
How the answer is worked out
“Percent” means “per hundred”, so 5% is 5 out of every 100, or 0.05 as a decimal. Taking 5% of 21 means multiplying 21 by 0.05, which gives 1.05.
1.05 is the 5% share of 21. The remaining 95% is 19.95, and the two parts add back up to 21.
Why calculate this?
Taking a percentage of a number is how discounts, tips, tax and interest are worked out.
- Discounts: 5% off an item priced $21 saves $1.05, so you pay $19.95.
- Tips: a 5% tip on a bill of $21 is $1.05, so the total is $22.05.
- Interest: simple interest of 5% a year on $21 earns $1.05 in one year and $5.25 over five years.
- Tax: a sales tax of 5% on a price of $21 adds $1.05, so the price including tax is $22.05.
A quicker way
Use 10% and 1%: 10% of 21 is 2.1 and 1% is 0.21. 5% is 5 × 1% = 1.05 = 1.05.
Swap the numbers if that is easier: 5% of 21 is always the same as 21% of 5, because both are 5 × 21 ÷ 100.
Check the answer
Work backwards: 1.05 ÷ 21 × 100 = 5%. Getting 5% back shows the answer is right.
Rounding
Rounded to a whole number the result is 1, to one decimal place 1.1 and to two decimal places 1.05. Round only at the end: rounding halfway through a calculation can change the last digit.
The formula explained
result = percentage ÷ 100 × number. Dividing the percentage by 100 turns it into a decimal multiplier, so 25% becomes 0.25 and 150% becomes 1.5. Multiplying the number by that decimal gives the share.
Another worked example: 2% of 77
- Turn the percentage into a decimal: 2 ÷ 100 = 0.02
- Multiply: 0.02 × 77 = 1.54
Common percentages of 21
10% of 21 is 2.1, 20% is 4.2, a quarter (25%) is 5.25, half (50%) is 10.5 and three quarters (75%) is 15.75. Knowing these makes it easy to estimate any other percentage of 21 in your head.
Adding and taking away 5%
Increasing 21 by 5% gives 22.05 and decreasing it by 5% gives 19.95. These do not cancel out: raising 21 by 5% and then lowering the result by 5% ends at 20.9475, because the second 5% is taken of a bigger number.
Finding the original number
If 1.05 is 5% of something, divide by 0.05 to get it back: 1.05 ÷ 0.05 = 21. This is how you work out a price before tax or a full amount from a share of it.
Other ways to ask this
The same calculation is often asked in other words. All of these have the answer above:
- What is 5 percent of 21?
- 5% of 21
- 5 percent times 21
- Find 5% of 21
- How much is 5 per cent of 21?
Terms used on this page
- Percentage: the rate, the number with the % sign.
- Base: the number you take the percentage of.
- Decimal multiplier: the percentage divided by 100.
- Mark-up and discount: adding or taking away a percentage of a price.
The answer in other forms
| Result | 1.05 |
|---|---|
| Remaining | 19.95 |
| 5% as decimal | 0.05 |
| 21 + 5% | 22.05 |
Related results
| 10% of 21 | 10% of 21 = 2.1 |
| 15% of 21 | 15% of 21 = 3.15 |
| 20% of 21 | 20% of 21 = 4.2 |
| 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 5
Doing it in a spreadsheet
In Excel, Google Sheets or Numbers type =5%*21 into any cell. Replace the numbers with cell references (for example A1 and B1) to reuse the formula for a whole column.
Common mistakes
Forgetting to divide the percentage by 100 makes the answer 100 times too big. Note that x% of y always equals y% of x.
Practice examples
| 2% of 77 | Show answer2% of 77 = 1.54 |
| 19% of 37 | Show answer19% of 37 = 7.03 |
| 99% of 73 | Show answer99% of 73 = 72.27 |
| 49% of 4 | Show answer49% of 4 = 1.96 |
| 11% of 22 | Show answer11% of 22 = 2.42 |
| 72% of 32 | Show answer72% of 32 = 23.04 |
| 33% of 72 | Show answer33% of 72 = 23.76 |
| 19% of 86 | Show answer19% of 86 = 16.34 |
| 86% of 12 | Show answer86% of 12 = 10.32 |
| 88% of 87 | Show answer88% of 87 = 76.56 |
How this answer was calculated
The result is worked out from the numbers in this page's address when the page is opened, using exact arithmetic wherever possible and rounding only for display. Nothing is copied from a printed table. If you think an answer is wrong, please tell us through the contact page and we will check it.
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Questions
What is 5 Percent of 21?
5% of 21 is 1.05. Formula, steps and practice examples.
What is 5% off 21?
19.95. Taking 5% off leaves 95% of 21.
What is 21 plus 5%?
22.05. Adding 5% is the same as multiplying by 1.05.
What is 5% of 21 as a fraction?
5/100 × 21 = 105/100, which simplifies to 21/20.
How do I find 5% of a number on a calculator?
Multiply the number by 0.05. For 21 that is 21 × 0.05 = 1.05. On many calculators you can also type 21 × 5 %.