Fraction Calculator

Add, subtract, multiply, and divide fractions

About Fraction Calculator

Fraction Calculator does one operation on two fractions: add, subtract, multiply, or divide. Each box takes a whole number, a decimal such as 0.75, or a fraction, and the small box on the left turns an entry into a mixed number. The arithmetic uses exact whole numbers of any length, so a 20-digit numerator is not rounded. You get the result reduced to lowest terms, as a mixed number when it differs, and as a decimal written exactly, with repeating digits in brackets, followed by the steps of the calculation, worked out by the page with whole-number arithmetic.

Example

Three calculations and what the page shows (the page's own fraction code, run in Node on October 6, 2026).

You enter

1 (whole) and 1/2  +  3/4
1/6  /  2/3
22/7  *  1/1

Result and steps

9/4 = 2 1/4 (mixed number) = 2.25
  1 and the fraction = 3/2 as an improper fraction
  Least common denominator of 2 and 4: 4
  3/2 = 6/4 and 3/4 = 3/4
  6/4 + 3/4 = 9/4
1/4 = 0.25
  Dividing by 2/3 is multiplying by its reciprocal 3/2
  (1 × 3) / (6 × 2) = 3/12
  Simplify by 3: 1/4
22/7 = 3 1/7 (mixed number) = 3.(142857)
  Multiply across: (22 × 1) / (7 × 1) = 22/7

How to add, subtract, multiply, or divide fractions

1Type each numerator above the line and each denominator below it; a box may also hold a decimal such as 0.5.
2For a mixed number such as 1 1/2, put the 1 in the small box on the left, with any minus sign there.
3Pick "+", "-", "*", or "/" between the two fractions.
4Click "Calculate" to get the reduced fraction, the mixed number, the decimal, and the numbered steps.

Formats and limits

Entries: Whole numbers, decimals, and fractions such as 3/-4 in any box; a whole part in the small box for a mixed number
Number size: Any length: exact integer arithmetic, never rounded
Decimal: Exact; the repeating part is shown in brackets, and a period longer than 100 digits is cut with a note
Reported instead of a result: A zero denominator, division by zero, and text that is not a number

Where your fractions are processed

All the arithmetic is done by this page in your browser, and your numbers are not sent anywhere. When an error message is shown, its text goes to our error log with the tool's name and your browser's name and major version, and whatever it quotes from your entries is replaced by a placeholder.

Frequently asked questions

Is the answer always in lowest terms?

Yes. Every result is divided by the greatest common divisor of its numerator and denominator, and the minus sign moves to the numerator, so 1/-2 is shown as -1/2. When that division changes something, a step names the number it divided by.

Can I enter mixed numbers?

Yes. Type the whole part in the small box before the fraction: 1 there, then 1 over 2, means 1 1/2. For a negative mixed number, put the minus on the whole part only, as in -1 and 1/2; a minus inside the fraction as well is refused with a message.

Is the decimal exact?

Yes. 9/8 is written 1.125, and a repeating decimal shows its period in brackets: 1/6 is 0.1(6) and 22/7 is 3.(142857). When the period runs past 100 digits, the digits are cut, never rounded, and a note says the repeating part is longer.

What happens if I divide by zero?

No result is given. Dividing by a fraction equal to zero shows Cannot divide by zero, and so does a 0 typed in a denominator box; a fraction typed in one box, such as 1/0, is reported as an error that quotes it.

Tips and tricks

✓To compare two fractions, subtract one from the other: a negative result means the first one is smaller.