Fraction Calculator
Add, subtract, multiply and divide fractions, and get the answer simplified to lowest terms — with the mixed-number form and decimal equivalent shown alongside.
Result
How It Works
A fraction is a part of a whole: the numerator (top number) counts the parts you have, and the denominator (bottom number) counts how many equal parts the whole is split into. Adding and subtracting fractions needs a common denominator — the bottom numbers must match before the top numbers can be combined. Multiplying is simpler: multiply the numerators together and the denominators together. Dividing means flipping the second fraction and multiplying instead.
Every answer is then simplified to lowest terms by dividing the numerator and denominator by their greatest common divisor (GCD). The GCD of 6 and 20, for example, is 2, so 6/20 simplifies to 3/10. When an answer is an improper fraction (top number larger than the bottom), the calculator also shows it as a mixed number, which is how measurements usually appear in recipes and DIY.
Worked examples: 1/2 + 1/3 = 3/6 + 2/6 = 5/6 (about 0.8333). 3/4 ÷ 2/5 = 3/4 × 5/2 = 15/8 = 1 7/8 (1.875). 3/4 × 2/5 = 6/20 = 3/10 (0.3).
How to Use This Calculator
Enter two fractions and pick an operation — the result updates live as you type, with the full working shown underneath.
- Enter the first fraction — numerator first, then denominator. For one half, enter 1 and 2.
- Pick an operation — add, subtract, multiply or divide — from the dropdown.
- Enter the second fraction the same way, then read the answer: simplified fraction, mixed number and decimal, plus the step-by-step working.
The Reset button restores the example (1/2 + 1/3) so you can start over. Only whole numbers are accepted — if your input has a decimal, convert it to a fraction first (for example, 0.75 = 3/4).
Tips and Practical Advice
Fractions show up in cooking, woodworking, sewing and school maths — and most fraction mistakes come from rushing the denominator step. A few habits keep the answers right.
- Never add denominators. 1/2 + 1/3 is not 2/5 — the denominators must be made equal first (here, 6), and only the numerators are added.
- Simplify before multiplying. Cancelling common factors first keeps the numbers small: in 3/4 × 2/5, cancelling 2 and 4 gives 3/2 × 1/5 = 3/10 directly.
- Use mixed numbers for real measurements. A recipe or a cut list reads better as 1 7/8 cups or inches than as 15/8 — the calculator shows both forms so you can pick.
- Check with the decimal. If 5/6 should be a bit under 1, the decimal 0.8333 confirms it — a quick sense-check catches a mistyped numerator.
Frequently Asked Questions
How do you add fractions with different denominators?
Find a common denominator, convert both fractions, then add the numerators. For 1/2 + 1/3, the common denominator is 6: 3/6 + 2/6 = 5/6.
How do you divide fractions?
Flip the second fraction (its reciprocal) and multiply. 3/4 ÷ 2/5 = 3/4 × 5/2 = 15/8 = 1 7/8.
What does simplify to lowest terms mean?
It means dividing the numerator and denominator by their greatest common divisor until they share no common factor except 1. 6/20 simplifies to 3/10 because both divide by 2.
What is a mixed number?
A mixed number combines a whole number with a proper fraction, like 1 7/8. It is the same value as the improper fraction 15/8, just written in a form that is easier to read as a measurement.
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