Fraction Calculator
Add, subtract, multiply, or divide fractions with step-by-step working shown.
Written by Golam Rabbani, Founder & Lead Engineer — Last updated 2026-06-01
How to use this fraction calculator
- For a whole or mixed number, enter the whole part in the optional whole-number field beside each fraction row (e.g. enter 1 in the whole field and 2/3 in the numerator/denominator fields to represent 1 2/3).
- Enter the numerator and denominator for the first fraction. The operator shown on each added row (+ − × ÷) controls how that fraction combines with the previous one.
- Click "+ Add fraction" to include a third, fourth, or more fractions in a single calculation, then choose the operator for each new row.
- Press Calculate to see the result as a simplified fraction, mixed number, decimal, and percentage, plus a full step-by-step working panel.
- Note: when three or more fractions are combined, operations are evaluated strictly left to right with no operator precedence — for example, 1/2 + 1/2 x 4 equals 4, not 2 1/2.
- Use Copy to save the result to your clipboard, or Reset to clear all fields and start over.
About this fraction calculator
The fraction calculator adds, subtracts, multiplies, and divides any number of fractions — including whole numbers and mixed numbers — and returns the answer as a simplified fraction, a mixed number, a decimal, and a percentage, all at once. You can enter values with three fields per fraction (whole, numerator, denominator) or switch to Expression mode and type a single line such as 1 2/3 + 2/3 × 4, optionally using the on-screen keypad on a phone.
Enter a mixed number by filling in the optional whole-number field beside a fraction row. The tool converts it to an improper fraction internally using whole × denominator + numerator, all over the denominator — so 1 2/3 becomes (1 × 3 + 2) / 3 = 5/3 — and shows that conversion as the first step.
Adding or subtracting unlike denominators (the LCD method): to compute 3/4 + 5/6, first find the lowest common denominator. The LCD is the least common multiple of the denominators, which equals d1 × d2 / GCD(d1, d2). Here GCD(4, 6) = 2, so the LCD = 4 × 6 / 2 = 12. Rewrite each fraction over 12 by multiplying by the factor that scales its denominator up: 3/4 = 9/12 (×3) and 5/6 = 10/12 (×2). Now combine the numerators: 9/12 + 10/12 = 19/12. Since 19 is prime to 12 the fraction is already in lowest terms, giving the mixed number 1 7/12 ≈ 1.5833.
Multiplying and dividing: multiplication needs no common denominator — multiply straight across, so 2/3 × 4/5 = (2 × 4) / (3 × 5) = 8/15. Division multiplies by the reciprocal of the second fraction (flip it, then multiply): 2/3 ÷ 4/5 = 2/3 × 5/4 = 10/12 = 5/6.
Simplifying with the Euclidean algorithm: every result is reduced by dividing the numerator and denominator by their greatest common divisor. To reduce 18/24, GCD(18, 24) = 6, so 18 ÷ 6 over 24 ÷ 6 = 3/4. The Euclidean algorithm finds that GCD quickly by repeatedly replacing the larger number with its remainder modulo the smaller until one becomes zero.
When three or more fractions are chained, the calculator evaluates strictly left to right with no operator precedence. For example, 1/2 + 1/2 × 4 is computed as (1/2 + 1/2) × 4 = 1 × 4 = 4, not as 1/2 + (1/2 × 4) = 2 1/2. The step-by-step panel makes every intermediate result visible.
Worked example: 1 2/3 + 2/3. The mixed number 1 2/3 becomes 5/3. The LCD of 3 and 3 is 3, so 5/3 + 2/3 = 7/3, which is already in lowest terms, displayed as the mixed number 2 1/3, decimal 2.333…, and percentage 233.33%. Calculate writes your inputs into the page URL, so you can bookmark or share the exact result with the Copy Link button.
FAQ
- Can it handle mixed numbers?
- Yes. Each fraction row has an optional whole-number field. Enter the whole part there and the fractional part in the numerator and denominator fields — for example, whole 1, numerator 2, denominator 3 represents 1 2/3. The tool converts it to an improper fraction (5/3) internally and shows that conversion step in the working panel.
- Can I calculate more than two fractions?
- Yes. Click the "+ Add fraction" button to append a third, fourth, or more rows. Each added row has its own operator selector (+ − x /) so you can mix operations freely across the chain.
- In what order are operations applied?
- Strictly left to right, with no operator precedence. For example, 1/2 + 1/2 x 4 is evaluated as (1/2 + 1/2) x 4 = 4, not as 1/2 + (1/2 x 4) = 2 1/2. The tool states this rule in the interface and shows each intermediate result in the step-by-step working panel.
- How does the fraction calculator simplify results?
- After computing the raw numerator and denominator, the tool divides both by their greatest common divisor (GCD), found using the Euclidean algorithm. This always produces the fraction in its lowest terms — for example, 6/8 becomes 3/4.
- What formula does the tool use for adding and subtracting fractions with unlike denominators?
- It converts both fractions to a common denominator using the lowest common denominator (LCD = d1 x d2 / GCD(d1, d2)), adjusts each numerator accordingly, then adds or subtracts. For multiplication it multiplies numerators and denominators directly; for division it multiplies by the reciprocal.
- Can I enter negative fractions?
- Yes. Enter a negative sign in the numerator field (e.g. -3 over 4) and the calculator will handle it correctly, propagating the sign through all operations and showing the correct simplified result.
- Does it show the answer as a decimal and percentage too?
- Yes. Alongside the simplified fraction, every result panel shows the equivalent decimal and percentage, plus the mixed-number form when the answer is improper. That makes it easy to copy whichever format your homework or spreadsheet needs without a second conversion step.
- Can I share or bookmark a calculation?
- Yes. When you press Calculate, your fractions and operators are written into the page URL. Reloading restores the same calculation, and the Copy Link button copies that URL so you can bookmark it or send the exact answer to someone else.
- Can I type the whole expression on one line instead of using the boxes?
- Yes. Switch to Expression mode and type something like 1 2/3 + 2/3 × 4 — use / for the fraction bar and ÷ for division. On a phone you can tap Show keypad for an on-screen math keypad. The field-based mode with separate whole, numerator, and denominator boxes is still available if you prefer it.
- Is the fraction calculator free?
- Yes, it is completely free to use with no signup, no account, and no usage limit.