deftools.io Math & Data

Fraction Calculator

Add, subtract, multiply, and divide fractions and mixed numbers. Auto-simplifies to lowest terms, shows step-by-step work, converts between fractions, mixed numbers, and decimals.

Fraction A
whole
Fraction B
whole
Try an example

About this tool

A fraction calculator does arithmetic on fractions and mixed numbers without losing precision to rounding. Type in two fractions and pick an operation — add, subtract, multiply, or divide — and the result is automatically reduced to lowest terms. Each step is shown in plain text, so it works well for checking homework or following along.

Example: 1 1/2 + 3/42 1/4 (steps: common denominator 4, 6/4 + 3/4 = 9/4 = 2 1/4). The Simplify tab reduces any fraction (e.g. 12/182/3), the Fraction → Decimal tab converts values like 3/40.75, and the Decimal → Fraction tab handles repeating decimals: 0.1(6)1/6.

Mixed numbers use the top "whole" field; leave it 0 for proper or improper fractions. Negative numbers are supported in every field.

FAQ

How do I enter a mixed number like 2 3/4?

Put 2 in the top "whole" field, 3 in the numerator, and 4 in the denominator. Leave the whole field as 0 for a plain fraction like 3/4.

What does the "GCD" number in the steps mean?

GCD stands for greatest common divisor — the largest integer that divides both the numerator and denominator. Dividing both by the GCD reduces the fraction to its simplest form.

Why does 0.(3) convert to 1/3?

Parentheses mark the repeating part of a decimal. 0.(3) means 0.3333... forever, which equals exactly 1/3. The tool uses long division to detect the repeating cycle and convert it to a fraction.

Can I divide by zero?

No — dividing by a zero fraction or setting a denominator to 0 shows an error, because the result is undefined.

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