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Fraction Calculator

Add, subtract, multiply or divide fractions instantly

Privacy: your files never leave your device. All processing happens locally in your browser.

How to use

  1. 1.Type the numerator (top) and denominator (bottom) of the first fraction into the first fraction box.
  2. 2.Pick the operation — +, −, ×, or ÷ — from the dropdown, then enter the numerator and denominator of the second fraction.
  3. 3.Read the simplified fraction, mixed number, and decimal instantly below, along with the worked-out steps — no button to press.

About Fraction Calculator

A fraction calculator combines two fractions with a single operation — addition, subtraction, multiplication, or division — and returns the answer in lowest terms, as a mixed number, and as a decimal. Enter the numerator and denominator of each fraction, choose +, −, ×, or ÷, and the result appears the moment you finish typing. Nothing is sent to a server; every step runs in your browser.

The four rules are short. To add or subtract, the fractions first need a common denominator, so a/b ± c/d = (a·d ± c·b) / (b·d). For example, 1/2 + 1/3 becomes (1·3 + 1·2) / (2·3) = 5/6. Multiplication is the easy one: multiply straight across, (a·c) / (b·d), so 2/3 × 3/4 = 6/12. Division flips the second fraction and multiplies, (a·d) / (b·c), which is why 1/2 ÷ 1/4 = (1·4) / (2·1) = 4/2 = 2 — dividing by a quarter asks how many quarters fit, and the answer is two.

Every result is then reduced to its simplest form. The calculator finds the greatest common divisor (GCD) of the numerator and denominator using the Euclidean algorithm and divides both by it, so 6/12 becomes 1/2 and 6/8 becomes 3/4. Reducing does not change the value of a fraction; it just states it with the smallest possible whole numbers, which is almost always how a final answer should be written.

When the top is larger than the bottom you have an improper fraction, and the tool also shows it as a mixed number. It divides the numerator by the denominator: the whole-number part is the quotient and the leftover becomes the new numerator. So 7/3 is 2 1/3, and −7/3 is −2 1/3 with the sign kept correct. The decimal column gives a quick sense of size, marked as exact for terminating decimals like 1/2 = 0.5 and approximate for repeating ones like 1/3 ≈ 0.3333333333.

All arithmetic is done with integers and simplified only at the end, so there is no floating-point drift — 1/3 + 1/3 + 1/3 style rounding errors do not appear. Negative numerators are allowed and the sign is normalised onto the numerator, so 1/−2 is treated as −1/2. A denominator of zero, or dividing by a fraction whose numerator is zero, is flagged rather than silently returning a wrong value.

Use it for homework and test prep, adjusting recipe quantities, splitting measurements in woodworking and sewing, converting between fractions and decimals, or any everyday moment where you need an exact fractional answer instead of a rounded one. Because the numbers are whole and the steps are shown, it doubles as a way to check work you have done by hand.

Frequently asked questions

How do you add or subtract fractions with different denominators?
Give them a common denominator first: a/b ± c/d = (a·d ± c·b) / (b·d). For 1/2 + 1/3 that is (1·3 + 1·2) / (2·3) = 5/6, and 1/2 − 1/3 = (3 − 2) / 6 = 1/6. This calculator does the cross-multiplication and simplification for you automatically.
How do you multiply and divide fractions?
To multiply, multiply the numerators together and the denominators together: (a/b) × (c/d) = (a·c) / (b·d), so 2/3 × 3/4 = 6/12 = 1/2. To divide, flip the second fraction and multiply: (a/b) ÷ (c/d) = (a·d) / (b·c), so 1/2 ÷ 1/4 = 4/2 = 2.
How does the calculator simplify a fraction to lowest terms?
It finds the greatest common divisor (GCD) of the numerator and denominator with the Euclidean algorithm, then divides both by it. For example 6/8 has a GCD of 2, so it reduces to 3/4, and 2/4 reduces to 1/2. The value stays the same; only the numbers get smaller.
How do I turn an improper fraction into a mixed number?
Divide the numerator by the denominator. The quotient is the whole number and the remainder becomes the new numerator over the same denominator. So 7/3 = 2 1/3, because 3 goes into 7 twice with 1 left over. The calculator shows the mixed number automatically, keeping the sign correct for negatives like −7/3 = −2 1/3.
Can it handle negative fractions and whole numbers?
Yes. Enter a minus sign on a numerator or denominator and the sign is normalised onto the numerator, so 1/−2 is treated as −1/2 and the result's sign is correct. For a whole number, write it over 1 (for example 5 = 5/1). Decimals aren't accepted directly — convert them to a fraction first, such as 1.5 = 3/2.

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