What is 80 Percent of 15?
80% of 15 = 12
Step by step
- Turn the percentage into a decimal: 80 ÷ 100 = 0.8
- Multiply: 0.8 × 15 = 12
How the answer is worked out
“Percent” means “per hundred”, so 80% is 80 out of every 100, or 0.8 as a decimal. Taking 80% of 15 means multiplying 15 by 0.8, which gives 12.
12 is the 80% share of 15. The remaining 20% is 3, and the two parts add back up to 15.
Why calculate this?
Taking a percentage of a number is how discounts, tips, tax and interest are worked out.
- Discounts: 80% off an item priced $15 saves $12, so you pay $3.
- Tips: a 80% tip on a bill of $15 is $12, so the total is $27.
- Interest: simple interest of 80% a year on $15 earns $12 in one year and $60 over five years.
- Tax: a sales tax of 80% on a price of $15 adds $12, so the price including tax is $27.
A quicker way
Use 10% and 1%: 10% of 15 is 1.5 and 1% is 0.15. 80% is 8 × 10% = 12 = 12.
Swap the numbers if that is easier: 80% of 15 is always the same as 15% of 80, because both are 80 × 15 ÷ 100.
Check the answer
Work backwards: 12 ÷ 15 × 100 = 80%. Getting 80% back shows the answer is right.
Rounding
Rounded to a whole number the result is 12, to one decimal place 12.0 and to two decimal places 12.00. 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: 16% of 70
- Turn the percentage into a decimal: 16 ÷ 100 = 0.16
- Multiply: 0.16 × 70 = 11.2
Common percentages of 15
10% of 15 is 1.5, 20% is 3, a quarter (25%) is 3.75, half (50%) is 7.5 and three quarters (75%) is 11.25. Knowing these makes it easy to estimate any other percentage of 15 in your head.
Adding and taking away 80%
Increasing 15 by 80% gives 27 and decreasing it by 80% gives 3. These do not cancel out: raising 15 by 80% and then lowering the result by 80% ends at 5.4, because the second 80% is taken of a bigger number.
Finding the original number
If 12 is 80% of something, divide by 0.8 to get it back: 12 ÷ 0.8 = 15. 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 80 percent of 15?
- 80% of 15
- 80 percent times 15
- Find 80% of 15
- How much is 80 per cent of 15?
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 | 12 |
|---|---|
| Remaining | 3 |
| 80% as decimal | 0.8 |
| 15 + 80% | 27 |
Related results
| 5% of 15 | 5% of 15 = 0.75 |
| 10% of 15 | 10% of 15 = 1.5 |
| 15% of 15 | 15% of 15 = 2.25 |
| 20% of 15 | 20% of 15 = 3 |
| 25% of 15 | 25% of 15 = 3.75 |
| 50% of 15 | 50% of 15 = 7.5 |
| 75% of 15 | 75% of 15 = 11.25 |
The other way round: 15% of 80
Doing it in a spreadsheet
In Excel, Google Sheets or Numbers type =80%*15 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
| 16% of 70 | Show answer16% of 70 = 11.2 |
| 2% of 95 | Show answer2% of 95 = 1.9 |
| 70% of 92 | Show answer70% of 92 = 64.4 |
| 70% of 75 | Show answer70% of 75 = 52.5 |
| 90% of 93 | Show answer90% of 93 = 83.7 |
| 35% of 16 | Show answer35% of 16 = 5.6 |
| 12% of 85 | Show answer12% of 85 = 10.2 |
| 54% of 45 | Show answer54% of 45 = 24.3 |
| 94% of 56 | Show answer94% of 56 = 52.64 |
| 75% of 42 | Show answer75% of 42 = 31.5 |
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 80 Percent of 15?
80% of 15 is 12. Formula, steps and practice examples.
What is 80% off 15?
3. Taking 80% off leaves 20% of 15.
What is 15 plus 80%?
27. Adding 80% is the same as multiplying by 1.8.
What is 80% of 15 as a fraction?
80/100 × 15 = 1200/100, which simplifies to 12/1.
How do I find 80% of a number on a calculator?
Multiply the number by 0.8. For 15 that is 15 × 0.8 = 12. On many calculators you can also type 15 × 80 %.