How this calculator works
The calculation retains integer numerators and denominators through each operation, then reduces using the greatest common divisor. A negative denominator is normalized to the numerator. Each input is limited to one million in magnitude to keep intermediate integers exact; the decimal result is an approximation.
The formula
Add: a/b + c/d = (ad + bc)/(bd)
Subtract: (ad − bc)/(bd)
Multiply: ac/(bd)
Divide: ad/(bc)
Reduce numerator and denominator by their greatest common divisor.A quick example
1/2 + 1/3 = 5/6, approximately 0.833333. Multiplying 3/2 by 4/3 gives 12/6, which simplifies to 2/1.
How to use this calculator
- Enter integer numerator and denominator for each fraction.
- Choose the operation.
- Review the exact and simplified fractions; use the decimal only as an approximation.
A few common questions
Are improper fractions supported?
Yes. Numerators may exceed denominators and the result remains a fraction rather than a mixed number.
Where should I put a negative sign?
Either numerator or denominator may be negative. The final denominator is displayed positive.
Can I divide by a zero fraction?
No. A zero numerator in the second fraction makes division undefined.