Fraction Calculator
Add, subtract, multiply and divide fractions and mixed numbers — with the answer in lowest terms, as a mixed number and decimal, and the working shown.
- All four operations
- With steps
- Decimal ↔ fraction
- Private
Type fractions as 3/4, mixed numbers with a space as 1 3/4, or whole numbers and decimals such as 0.75.
Step by step
How to calculate with fractions
Type them the way you write them.
- 1
Choose what to do
Calculate with two fractions, simplify or convert a single one, or compare two.
- 2
Type the fractions
Write 3/4 for a fraction, 1 3/4 (with a space) for a mixed number, or a whole number or decimal.
- 3
Read the answer
You get the result in lowest terms, as a mixed number, decimal and percent, plus each step of the calculation.
The answer and the reasoning
Built for homework, recipes and workshop measurements.
Four operations
Addition, subtraction, multiplication and division of fractions, mixed numbers and whole numbers.
Every step shown
Common denominators, multiplying across, flipping the divisor and reducing — written out.
Lowest terms
Results are reduced automatically; the simplify mode shows the greatest common divisor used.
Decimals and percent
Convert 0.375 to 3/8 or 5/8 to 0.625 and 62.5 %; repeating decimals are identified.
Compare fractions
See which of two fractions is larger, their common denominator and the difference.
Link to your calculation
Copy a link that reopens the calculator with your numbers filled in — handy for sharing or saving a scenario.
Made for phones
Large fields, the right keyboard for numbers and a layout that fits small screens.
Private by design
Everything is calculated in your browser. Your numbers are not sent to a server.
The rules of fraction arithmetic
To add or subtract fractions they need the same denominator. Find the least common denominator, rewrite both fractions, then add or subtract the numerators: 1/2 + 3/4 = 2/4 + 3/4 = 5/4, which is 1 1/4 as a mixed number. Fractions that already share a denominator are simply combined across the top.
To multiply, multiply the numerators together and the denominators together: 2/3 × 3/5 = 6/15 = 2/5. To divide, multiply by the reciprocal of the second fraction — flip it and multiply: 3/4 ÷ 2/5 = 3/4 × 5/2 = 15/8. Mixed numbers are first turned into improper fractions: 1 3/4 = 7/4.
A fraction is in lowest terms when numerator and denominator share no factor other than 1. Divide both by their greatest common divisor: for 18/24 it is 6, giving 3/4. To convert to a decimal, divide the numerator by the denominator; fractions whose denominator has factors other than 2 and 5 produce repeating decimals, such as 1/3 = 0.333…
Common fractions as decimals and percent
| Fraction | Decimal | Percent |
|---|---|---|
| 1/8 | 0.125 | 12.5 % |
| 1/4 | 0.25 | 25 % |
| 1/3 | 0.333… | 33.3 % |
| 1/2 | 0.5 | 50 % |
| 2/3 | 0.666… | 66.7 % |
| 3/4 | 0.75 | 75 % |
Tips
- Working with ratios such as 3 : 4 instead? Use the Ratio Calculator.
- Turn a fraction into “percent of” questions with the Percentage Calculator.
- For longer expressions with brackets, powers and roots, open the Scientific Calculator.
- Estimate before you calculate: 5/8 + 1/3 must be a little under 1, because 5/8 is just over a half and 1/3 is under a half.
Frequently asked questions
Can’t find your answer? Contact us — we reply quickly.
How do I add fractions with different denominators?
Rewrite both fractions with the least common denominator, add the numerators and simplify. Example: 1/4 + 1/6 = 3/12 + 2/12 = 5/12.
How do I divide fractions?
Keep the first fraction, flip the second and multiply: 2/3 ÷ 4/5 = 2/3 × 5/4 = 10/12 = 5/6.
How do I simplify a fraction?
Divide the numerator and the denominator by their greatest common divisor. For 18/24 the divisor is 6, so the fraction simplifies to 3/4.
How do I enter a mixed number?
Type the whole number, a space and the fraction: 2 1/2 means two and a half. Negative values start with a minus sign.
How do I convert a decimal to a fraction?
Choose “Simplify / convert” and type the decimal. 0.375 becomes 375/1000, which reduces to 3/8.
Are my numbers stored or sent anywhere?
No. The calculation runs in your browser. Your last inputs are remembered on your own device only, so the form is still filled in when you come back; use Reset to clear them.
More free calculators
Money, dates, maths, health and home projects — quick answers that are worked out in your browser.