➗ Arithmetic 🧮 Math Updated2026-07-18
Fraction Calculator.
⚡
Quick answer
Enter two fractions and an operation. To add or subtract, use a common denominator: a/b ± c/d = (a·d ± c·b)/(b·d). To multiply, go straight across; to divide, flip the second and multiply. Every answer is reduced to lowest terms and shown as a decimal.
½
Fraction Calculator
=
5
4
Mixed number: 1 1/4
Decimal: 1.25
Simplified to lowest terms
✨ Live · Reduces to lowest terms and shows mixed-number and decimal forms. Negative numerators are allowed.
📊 Quick reference
Common fractions to decimals & percent.
| Fraction | Decimal | Percentage |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/3 | 0.333… | 33.33% |
| 2/3 | 0.667… | 66.67% |
| 1/4 | 0.25 | 25% |
| 3/4 | 0.75 | 75% |
| 1/5 | 0.2 | 20% |
| 1/8 | 0.125 | 12.5% |
| 3/8 | 0.375 | 37.5% |
| 5/8 | 0.625 | 62.5% |
| 1/10 | 0.1 | 10% |
| 1/16 | 0.0625 | 6.25% |
❓ FAQ
Common questions.
How do you add fractions with different denominators?
Give them a common denominator, then add the numerators. The quick method: multiply crosswise. For a/b + c/d, the sum is (a×d + c×b) ÷ (b×d). For example 1/2 + 3/4 = (1×4 + 3×2)/(2×4) = (4 + 6)/8 = 10/8, which reduces to 5/4 or 1¼. This calculator does the cross-multiplication and the reducing for you.
How do you multiply and divide fractions?
To multiply, multiply the numerators together and the denominators together: 2/3 × 3/4 = 6/12 = 1/2. To divide, flip the second fraction and multiply (multiply by the reciprocal): 1/2 ÷ 3/4 = 1/2 × 4/3 = 4/6 = 2/3. Dividing by a fraction is the same as multiplying by its upside-down version.
How do you simplify (reduce) a fraction?
Divide the numerator and denominator by their greatest common divisor (GCD). For 10/8, the GCD is 2, so it reduces to 5/4. A fraction is in "lowest terms" when the only number that divides both top and bottom is 1. This tool always returns the fully reduced answer.
How do you convert a fraction to a decimal or percentage?
Divide the numerator by the denominator to get the decimal: 3/8 = 3 ÷ 8 = 0.375. Multiply the decimal by 100 for the percentage: 0.375 = 37.5%. Some fractions like 1/3 give repeating decimals (0.333…). The reference table on this page lists the most common conversions.
What is a mixed number vs an improper fraction?
An improper fraction has a numerator larger than its denominator, like 5/4. A mixed number writes the same value as a whole part plus a proper fraction: 5/4 = 1¼. To convert, divide: 5 ÷ 4 = 1 remainder 1, so it's 1 and 1/4. This calculator shows both forms whenever the answer is bigger than 1.