Fraction Calculator
Add, subtract, multiply, and divide fractions — including mixed numbers. Results shown as simplified fraction, mixed number, and decimal. Runs entirely in your browser, no signup required.
First fraction
Second fraction
Result
How to Use the Fraction Calculator
- 1Enter the numerator and denominator for each fraction. For mixed numbers, also enter the whole number on the left.
- 2Select the operation — +, −, ×, or ÷ — from the buttons between the two fractions.
- 3The result appears instantly as a simplified fraction, mixed number, and decimal.
- 4Use the Simplify tab to reduce any single fraction to its lowest terms.
Fraction Rules at a Glance
Addition/Subtraction: requires a common denominator — find the LCM of both denominators, convert, then operate on numerators. Multiplication: numerator × numerator over denominator × denominator, then simplify. Division: multiply by the reciprocal of the divisor. Simplification: divide both numerator and denominator by their GCD.
Fraction Tips
Always simplify the result
After any fraction operation, check whether the result can be simplified. 6/8 and 3/4 are the same value — the simplified form is easier to work with.
Mixed numbers in algebra
When solving equations, convert mixed numbers to improper fractions first. 2½ = 5/2. Operations on improper fractions are more straightforward than mixed number arithmetic.
Cross-cancelling before multiply
When multiplying fractions, simplify across the fractions before multiplying to keep numbers small. 4/9 × 3/8: cancel 4 and 8 (÷4), cancel 3 and 9 (÷3) → 1/6.
Division is multiplication
Dividing by a fraction is the same as multiplying by its reciprocal. A÷B/C = A×C/B. This rule never changes — memorize it and fraction division becomes straightforward.
Check with decimals
The decimal equivalent shown in the result lets you quickly sanity-check your answer. 7/4 = 1.75 — if the decimal makes sense, the fraction is likely correct.
Negative fractions
Enter a negative sign in the numerator field for negative fractions. A negative denominator is automatically moved to the numerator during simplification.
Frequently Asked Questions
How do you add fractions with different denominators?
Find the least common denominator (LCD) of both fractions, convert each fraction to an equivalent fraction with the LCD, then add the numerators. For example: 1/3 + 1/4. LCD = 12. So 1/3 = 4/12 and 1/4 = 3/12. Sum = 7/12. The calculator does this automatically.
How do you multiply fractions?
Multiply the numerators together and the denominators together, then simplify. For example: 2/3 × 3/4 = 6/12 = 1/2. It is often easier to cross-cancel before multiplying: 2/3 × 3/4 — cancel the 3s to get 2/1 × 1/4 = 2/4 = 1/2.
How do you divide fractions?
Multiply the first fraction by the reciprocal (flip) of the second fraction. For example: 2/3 ÷ 4/5 = 2/3 × 5/4 = 10/12 = 5/6. The rule is "keep, change, flip" — keep the first fraction, change division to multiplication, flip the second fraction.
How do I enter mixed numbers?
Enter the whole number in the leftmost field and the fractional part in the numerator and denominator fields. For example, to enter 2½, type 2 in the whole field, 1 in the numerator, and 2 in the denominator.
How do I simplify a fraction?
Switch to the Simplify tab, enter the numerator and denominator, and the calculator shows the simplified form, the GCD used, the decimal, and the mixed number equivalent. Simplification divides numerator and denominator by their greatest common divisor (GCD).
What is the GCD and why does it matter for simplification?
GCD (Greatest Common Divisor) is the largest number that divides both the numerator and denominator evenly. Dividing both by the GCD gives the simplest form. For 6/9: GCD(6,9) = 3, so 6/9 simplifies to 2/3.