Fraction calculator
Add, subtract, multiply or divide two fractions. The answer is automatically simplified to its lowest terms.
Fill in the fields and press Calculate to see your result here.
How this calculation works
To add or subtract fractions, DoIt Calculators puts both over a common denominator (the product of the two denominators) before combining the numerators, then simplifies. To multiply, numerators and denominators multiply straight across; to divide, the second fraction is flipped and multiplied. The result is reduced using the greatest common divisor (GCD) of the numerator and denominator.
Tips
Whole numbers work too
Enter a whole number as a fraction over 1 (e.g. 5/1) to mix whole numbers into a calculation.
Negative fractions
Put the minus sign on the numerator (e.g. −3/4) rather than the denominator; the calculator handles the sign correctly either way.
Improper fractions are fine
An answer like 7/4 is perfectly valid. Divide 7 by 4 to see it as a mixed number, 1 and 3/4, or read the decimal shown under the result.
Dividing flips the second fraction
Dividing by a fraction is the same as multiplying by its reciprocal, so 1/2 ÷ 1/4 becomes 1/2 × 4/1, which is 2.
Results are always reduced
Answers are simplified with the greatest common divisor, so 6/8 will appear as 3/4. Two fractions that look different can be equal once simplified.
Frequently asked questions
Does it simplify the answer automatically?
Yes. Every result is reduced to its lowest terms using the greatest common divisor of the numerator and denominator.
What if I enter 0 as a denominator?
A denominator of 0 is undefined, so the calculator will show an error instead of a result.
Can I see the answer as a decimal?
Yes, the decimal equivalent is shown alongside the simplified fraction.