How it works
Both inputs are converted to improper fractions first. Addition and subtraction go through a common denominator, multiplication multiplies straight across, and division flips the second fraction and multiplies. Every answer is reduced by the greatest common divisor and shown three ways: simplified, mixed and decimal.
1/2 + 1/3 → 3/6 + 2/6 → 5/6 ≈ 0.833
What you can enter
- Whole numbers: 2 means 2/1.
- Fractions: 3/4, including negatives like -1/2.
- Mixed numbers: 1 1/2 means one and a half.
Tips
- Dividing by zero (or by 0/5) is refused with an error instead of a nonsense answer.
- Very large numbers (over a billion) are refused to keep the arithmetic exact.
- Everything runs in your browser; nothing is uploaded.
Standards and sources
- Fraction arithmetic follows standard school mathematics (common denominators, GCD reduction)
Last reviewed October 12, 2026
Frequently asked questions
How do I enter a mixed number?
Type it with a space, like 1 1/2 for one and a half. Whole numbers (2) and plain fractions (3/4) work too, including negatives.
How are the steps computed?
Addition and subtraction go through a common denominator, multiplication goes straight across, and division flips the second fraction. The steps show the unsimplified intermediates before reduction.
Why was my division refused?
Dividing by zero — including by 0/5 — has no answer, so the tool reports an error instead of guessing.
How exact are the decimals?
The fraction itself is always exact. The decimal is rounded to 10 digits for display.