Fraction to Percentage Calculator
Enter the numerator and denominator of any fraction to convert it to a percentage.
Enter the numerator in the first field and the denominator in the second. For example, to convert 3/4: enter 3 and 4 → result is 75%.
How to convert a fraction to a percentage
A fraction expresses one number as a part of another. To convert to a percentage:
- Divide the numerator by the denominator.
- Multiply the result by 100.
Example: 3/4 → 3 ÷ 4 = 0.75 → 0.75 × 100 = 75%.
Common fractions as percentages
| Fraction | Decimal | Percentage |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/3 | 0.333… | 33.33% |
| 2/3 | 0.666… | 66.67% |
| 1/4 | 0.25 | 25% |
| 3/4 | 0.75 | 75% |
| 1/5 | 0.2 | 20% |
| 2/5 | 0.4 | 40% |
| 3/5 | 0.6 | 60% |
| 4/5 | 0.8 | 80% |
| 1/8 | 0.125 | 12.5% |
| 3/8 | 0.375 | 37.5% |
| 1/10 | 0.1 | 10% |
Converting test scores and ratios
The same method works for any ratio or score. If you scored 17 out of 20 on a test: 17 ÷ 20 = 0.85 × 100 = 85%. Enter 17 and 20 in the calculator above.
Converting mixed numbers to percentages
A mixed number has a whole part and a fraction part (e.g. 1¾). Convert it to an improper fraction first, then divide.
- Multiply the whole number by the denominator: 1 × 4 = 4.
- Add the numerator: 4 + 3 = 7. The improper fraction is 7/4.
- Divide: 7 ÷ 4 = 1.75 × 100 = 175%.
| Mixed number | Improper fraction | Percentage |
|---|---|---|
| 1½ | 3/2 | 150% |
| 1¼ | 5/4 | 125% |
| 2⅓ | 7/3 | 233.33% |
| 1⅗ | 8/5 | 160% |
| 3¼ | 13/4 | 325% |
Ratios to percentages
A ratio like 3:2 means “3 parts to 2 parts” — a total of 5 parts. To find what percentage the first part is, divide by the total number of parts.
| Ratio | Total parts | First part | Second part |
|---|---|---|---|
| 1:1 | 2 | 50% | 50% |
| 1:3 | 4 | 25% | 75% |
| 3:1 | 4 | 75% | 25% |
| 2:3 | 5 | 40% | 60% |
| 3:2 | 5 | 60% | 40% |
| 1:4 | 5 | 20% | 80% |
| 2:5 | 7 | 28.57% | 71.43% |
| 3:7 | 10 | 30% | 70% |
Grade and exam score conversion
An exam mark is a fraction: your score over the total marks available. Enter the numerator (your score) and denominator (total marks) in the calculator above to get your percentage instantly.
| Score | Out of | Percentage | Typical US grade |
|---|---|---|---|
| 57 | 60 | 95% | A |
| 51 | 60 | 85% | B |
| 45 | 60 | 75% | C |
| 38 | 60 | 63.3% | D |
| 17 | 20 | 85% | B |
| 38 | 50 | 76% | C+ |
| 72 | 80 | 90% | A− |
| 63 | 90 | 70% | C |
Also on this site
- Percentage Calculator — find X% of Y, or what percent X is of Y
- Percentage Of Calculator — find what X% of any number is
- How to Calculate Percentages — step-by-step guide with formulas
- Percentage Change Calculator — measure increase or decrease
FAQ
How do I convert 1/3 to a percentage?
1 ÷ 3 = 0.3333… × 100 = 33.33% (recurring). Enter 1 and 3 in the calculator above.
How do I convert 3/4 to a percentage?
3 ÷ 4 = 0.75 × 100 = 75%.
How do I convert 2/5 to a percentage?
2 ÷ 5 = 0.4 × 100 = 40%.
How do I convert a percentage back to a fraction?
Write the percentage as a fraction over 100 and simplify. 75% = 75/100 = 3/4. 40% = 40/100 = 2/5.
What is 7 out of 10 as a percentage?
7 ÷ 10 = 0.7 × 100 = 70%. Enter 7 and 10 in the calculator above.
What is 5 out of 8 as a percentage?
5 ÷ 8 = 0.625 × 100 = 62.5%.