How this calculation works
Find the largest positive rational quantity that fits an integer number of times into each input fraction.
THE FORMULA
Convert both fractions to a common denominator and take the gcd of their numeratorsA worked example
3/4 and 5/6 become 9/12 and 10/12, whose common divisor is 1/12.
Good to know
Fractions must be positive.
Reference: NIST DLMF, Functions of Number Theory (opens in a new tab) ↗
Read the result
Find the largest positive rational quantity that fits an integer number of times into each input fraction.
The primary result is labeled “Greatest rational divisor”. Keep the input definitions in view when comparing this result with another method.
Try a related calculation
Fractions must be positive.
For a related exercise, try the greatest common divisor.
A few questions, answered
How can I check the default inputs by hand?
3/4 and 5/6 become 9/12 and 10/12, whose common divisor is 1/12.
Which rule does this calculator apply?
Convert both fractions to a common denominator and take the gcd of their numerators