Fraction Calculator
Add, subtract, multiply and divide fractions and mixed numbers. The answer comes in lowest terms.
Quick answer: Type two fractions and choose +, −, × or ÷. For example 1/2 + 1/3 = 5/6, and 3/4 − 1/4 = 1/2. The answer is shown in lowest terms, as a mixed number and as a decimal.
How to use it
- For a mixed number like 2 1/2, type 2 in the whole box, 1 on top and 2 on the bottom. For a plain fraction, leave the whole box empty.
- Choose add, subtract, multiply or divide.
- The answer appears at once in lowest terms.
How each operation works
- Add or subtract: give the fractions the same bottom number, then add or subtract the tops. 1/2 + 1/3 = 3/6 + 2/6 = 5/6.
- Multiply: multiply the tops and multiply the bottoms. 2/3 × 3/4 = 6/12 = 1/2.
- Divide: flip the second fraction and multiply. 1/2 ÷ 1/4 = 1/2 × 4/1 = 2.
Common fractions as decimals and percents
| Fraction | Decimal | Percent |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/3 | 0.3333 | 33.33% |
| 2/3 | 0.6667 | 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% |
| 1/6 | 0.1667 | 16.67% |
| 5/6 | 0.8333 | 83.33% |
| 1/8 | 0.125 | 12.5% |
| 3/8 | 0.375 | 37.5% |
| 5/8 | 0.625 | 62.5% |
| 7/8 | 0.875 | 87.5% |
| 1/10 | 0.1 | 10% |
Why lowest terms?
A fraction is in lowest terms when the top and bottom share no common factor except 1. The calculator divides both by their greatest common divisor, so 6/12 becomes 1/2. The arithmetic uses exact whole numbers, so there are no rounding errors even with large fractions.
What people use it for
- Homework and tests
- Recipes and scaling
- Woodworking and sewing
- Checking a worksheet
Questions
How do I add fractions with different denominators?
Find a common bottom number, convert each fraction, then add the tops. The calculator does this for you.
How do I add mixed numbers?
Type the whole number in the whole box. Example: 1 1/2 + 2 1/4 = 3 3/4.
Can I use negative fractions?
Yes. Type a minus sign in the whole box, or in the top box when the whole box is empty.
What happens if I divide by zero?
The calculator tells you it cannot be done.
Is it free?
Yes. No sign-up, no install and no limit.
Is anything saved or sent?
No. Everything runs in your browser. Only your own best score, where a page shows one, is kept on your device.
Last updated 2026-10-24. Free to use, no sign-up. Made by ficklestudio26.