---
title: "Fraction Calculator — Add, Subtract, Multiply, Divide, Simplify (Step-by-Step)"
description: "Add, subtract, multiply, and divide fractions with full step-by-step working showing LCD, GCD, and simplification. Simplify fractions and convert decimals to fractions. Free."
url: "https://worldcalculators.org/calculators/fraction/"
canonical: "https://worldcalculators.org/calculators/fraction/"
---

# Fraction Calculator

Add, subtract, multiply, and divide fractions with full step-by-step working showing LCD, GCD, and simplification. Simplify fractions and convert decimals to fractions. Free.

## Quick answer

Add/Subtract: find LCD, convert, combine numerators, simplify.   Multiply: numerators × numerators, denominators × denominators, simplify.   Divide: flip the second fraction, then multiply (Keep–Change–Flip).   Simplify: divide both parts by their GCD.

## How Fraction Arithmetic Works

Find LCD first, convert fractions, then add numerators
Same as addition — common denominator, subtract numerators

## Frequently Asked Questions

Dividing by a fraction is the same as multiplying by its reciprocal. Mathematically: (a/b) ÷ (c/d) = (a/b) × (d/c) because multiplying by d/c "undoes" dividing by c/d. The mnemonic "Keep–Change–Flip" (or KCF) is standard in US/UK classrooms.
LCD (Least Common Denominator) = LCM (Least Common Multiple) of the denominators — used when adding or subtracting fractions. GCD (Greatest Common Divisor) = HCF (Highest Common Factor) — used when simplifying a fraction. In the UK, GCD is often called HCF.

Source: https://worldcalculators.org/calculators/fraction/
Markdown mirror of the HTML page. Prefer this URL for RAG; the interactive calculator still lives on the HTML page.