Online Tool Store
Fraction Calculator
Add, subtract, multiply, or divide fractions and see simplified, mixed-number, and decimal answers for free. Everything runs privately in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Calculate with two fractions
Enter whole-number numerators and non-zero denominators. Negative values are supported.
Example shown: 3/4 + 2/3. Replace any value or choose another operation.
Simplified answer
3/4 + 2/3
Mixed number
Decimal
Calculation
(3 × 3 + 2 × 4) / (4 × 3) = 17/12
The result is already in lowest terms.
How it works
- Enter the numerator and denominator for each fraction.
- Choose addition, subtraction, multiplication, or division.
- Read the exact simplified fraction, mixed number when applicable, decimal, and calculation method.
The fraction formulas
For fractions a/b and c/d, the four operations use these formulas:
Add: a/b + c/d = (a×d + c×b)/(b×d)
Subtract: a/b − c/d = (a×d − c×b)/(b×d)
Multiply: a/b × c/d = (a×c)/(b×d)
Divide: a/b ÷ c/d = (a×d)/(b×c)
After applying the selected formula, the calculator divides the new numerator and denominator by their greatest common factor. In the example, 3/4 + 2/3 = (3×3 + 2×4)/(4×3) = 17/12, which is already in lowest terms and equals 1 5/12.
FAQ
Does the calculator simplify every answer?
Yes. It finds the greatest common factor of the result numerator and denominator, then divides both by that factor so the exact answer is in lowest terms.
Can I calculate with negative fractions?
Yes. Put a minus sign on the numerator or denominator. The calculator normalizes the sign, so 1/-2 and -1/2 are treated as the same value.
Can I enter mixed numbers?
Enter a mixed number as an improper fraction: multiply the whole number by the denominator and add the numerator. For example, 1 3/4 becomes 7/4. Improper results are shown as mixed numbers automatically.
Why can I not divide by a zero fraction?
Division uses the reciprocal of the second fraction. A zero fraction has no reciprocal because flipping it would put zero in the denominator, so that operation is undefined.
Are my fractions sent anywhere?
No. The exact arithmetic and formatting run with JavaScript in your browser. No input, result, or calculation is uploaded.
How we compare
| Feature | Online Tool Store | CalculatorSoup | RapidTables |
|---|---|---|---|
| Add, subtract, multiply, and divide | Yes | Yes | Yes |
| Recalculates while you type | Yes | Calculate button | Equals button |
| Lowest-terms and mixed-number answer | Yes | Yes | Yes |
| Decimal beside the exact answer | Yes | Separate converter | Separate converter |
| Account required | No | No | No |
CalculatorSoup and RapidTables both cover standard fraction arithmetic. For a quick calculation between two proper or improper fractions, choose Online Tool Store Fraction Calculator: it updates immediately and keeps the simplified, mixed-number, and decimal answers together.