Add, subtract, multiply or divide fractions and mixed numbers, with steps.
Calculated instantly in your browser.
How do you add, subtract, multiply and divide fractions?
Use a/b + c/d = (ad + bc) / bd; a/b − c/d = (ad − bc) / bd; a/b × c/d = ac / bd; a/b ÷ c/d = ad / bc, then divide by the greatest common divisor to reduce. Addition and subtraction need a common denominator. Example: 1/2 + 1/3 puts both over 6 to give 3/6 + 2/6 = 5/6, already in lowest terms.
Understanding your result
Addition and subtraction need a common denominator; multiplication multiplies numerators and denominators straight across; division inverts the second fraction and multiplies. Every answer is reduced by its greatest common divisor so 4/8 shows as 1/2.
Formula and method
a/b + c/d = (ad + bc) / bd; a/b − c/d = (ad − bc) / bd; a/b × c/d = ac / bd; a/b ÷ c/d = ad / bc. The result is then divided by the greatest common divisor.
Assumptions and limitations
This tool adds, subtracts, multiplies and divides two fractions, mixed numbers or decimals, always reducing to lowest terms. Division by a fraction equal to zero is undefined and returns no result. Decimals are converted to fractions before calculating, so a rounded decimal may not reproduce the exact fraction you intended. It works with two values per operation.
Worked example
1/2 + 1/3: put over 6 to get 3/6 + 2/6 = 5/6, which is already in lowest terms.
How to use this tool
- Enter the first fraction (e.g. 1/2 or 1 1/2).
- Choose add, subtract, multiply or divide.
- Enter the second fraction and read the simplified answer.
Common mistakes to avoid
- Adding denominators together instead of finding a common one.
- Forgetting to convert a mixed number before calculating.
- Dividing by a fraction without inverting it first.
About the Fraction Calculator
The Fraction Calculator adds, subtracts, multiplies and divides fractions, mixed numbers and decimals. Enter two values, pick an operation, and get the answer as a simplified fraction, a mixed number and a decimal — with the working shown.
Who should use this tool
Students learning fractions, parents helping with homework, cooks scaling recipes, and tradespeople working in inches.
Benefits
- Handles whole numbers, fractions, mixed numbers and decimals.
- Answers are reduced to lowest terms automatically.
- Shows the worked steps, not just the result.
- Gives the mixed-number and decimal forms too.
Practical use cases
- Adding 1/2 and 1/3 for a maths exercise.
- Doubling or halving a recipe measured in cups.
- Combining fractional inch measurements on a build.
Frequently asked questions
Can I use mixed numbers and decimals?
Yes. Enter mixed numbers like 1 1/2, plain fractions like 3/4, whole numbers like 5, or decimals like 0.75 — the calculator handles them all.
Does it simplify the answer?
Always. The result is automatically reduced to lowest terms and also shown as a mixed number and a decimal.
What happens if I divide by zero?
Division by zero is undefined, so entering a second fraction that equals zero produces no valid answer. Dividing by a fraction works by inverting it and multiplying, but zero has no reciprocal to invert. Check that the divisor is a non-zero fraction, mixed number or decimal before running the calculation.