Fraction Calculator — Add, Subtract, Multiply, Divide
Add, subtract, multiply, and divide fractions with automatic simplification, mixed-number output, and decimal equivalents.
A fraction calculator that shows every form of the answer. Enter two fractions and an operator to get the simplified result, the mixed-number form, and the decimal equivalent. Handles negatives, improper fractions, and division-by-zero with explicit error messages.
Fraction arithmetic comes down to finding common denominators, multiplying straight across, or inverting and multiplying for division. The mechanical steps are simple but easy to slip on, especially when signs are involved or the numerator and denominator share a large common factor. This calculator runs the arithmetic, then reduces the result using the Euclidean GCD algorithm so you always see the lowest-terms answer.
Every result is shown three ways: the simplified fraction (for example 3/4), the mixed-number form if it's improper (1 1/4 for 5/4), and the decimal equivalent truncated to a clean length. Negative numerators or denominators work normally, and a zero in either denominator triggers a visible error instead of silently producing NaN. Preset examples cover one case per operator so you can verify the engine or pick a starting point. The display uses stacked fractions with a CSS border to match the way you'd write the math by hand.
- 1
Enter both fractions
Type a numerator and denominator for each side. Negatives are allowed on either value.
- 2
Pick an operator
Choose add, subtract, multiply, or divide. The result updates live as you edit any field.
- 3
Read three representations
See the simplified fraction, the mixed-number equivalent, and the decimal value side by side so you can use whichever form fits the task.
Homework checking
Verify a fraction-arithmetic answer and see the work broken into simplified, mixed, and decimal forms to spot where an error crept in.
Recipe scaling
Cut 3/4 cup in half without slipping on the arithmetic. Multiply 3/4 by 1/2 to get 3/8.
Carpentry measurements
Add 5/8 and 3/16 to find a combined length expressed in sixteenths, with a decimal readout for digital calipers.
How are fractions simplified?
The calculator divides both numerator and denominator by their greatest common divisor using the Euclidean algorithm. The result is always in lowest terms.
What happens with a zero denominator?
The tool shows a Denominator cannot be zero error and stops. Division by a zero numerator in the second fraction shows a separate Cannot divide by zero error.
Can it handle negative fractions?
Yes. A negative numerator, denominator, or whole result is preserved and displayed with a single leading minus sign.
Why are some decimals truncated?
The decimal display shows up to six digits after the point and strips trailing zeros for readability. The simplified fraction is always the exact answer.
Does it convert between improper fractions and mixed numbers?
Yes. Any improper result like 5/4 shows both the improper form and the mixed equivalent (1 1/4). Proper fractions show the same value in both boxes.