How to use it
- Type two numbers: fractions (3/4), mixed numbers (2 1/3), whole numbers or decimals.
- Pick +, −, × or ÷. The answer appears as a simplified fraction, a mixed number, an exact decimal and a percent, with the steps underneath.
- Convert any decimal or fraction in the box at the bottom.
Why exact matters
Most calculators turn fractions into decimals first, and decimals like 1/3 cannot be stored exactly, so answers come back as 0.49999999 instead of 1/2. This one keeps every number as a numerator and a denominator, using arbitrarily large integers, and reduces with the greatest common divisor after each operation. The decimal is then worked out by long division, which also reveals exactly where it starts repeating.
What we tested
On October 14, 2026 we ran the page’s own functions on 3,000 random sums, differences, products and quotients mixing whole numbers, fractions, mixed numbers, negatives and decimals, and compared each result with Python’s fractions module and an independent long-division expansion: 3,000 of 3,000 fractions and 3,000 of 3,000 decimals (including the repeating part) matched exactly. Division by zero is refused with a message. In Chromium: 2 1/3 + 3/4 showed 37/12 = 3 1/12 = 3.083 (the 3 repeating, drawn with a bar), 1 / 7 showed 0.142857 with the six repeating digits overlined, dividing by zero gave a message, 0.375 converted to 3/8, and the page fitted a 390 px phone screen with no errors
Sources
Checked on .
Frequently Asked Questions
Built by Derek Giordano · Part of Ultimate Design Tools