Use Common Factors and Common Multiples
The greatest common divisor is the largest positive integer that divides both inputs without a remainder.
A factor divides a number exactly
The greatest common divisor is the largest positive integer that divides both inputs without a remainder. For 24 and 36 it is 12. Dividing both terms of 24:36 by twelve reduces the ratio to 2:3.
A multiple works in the other direction
The least common multiple is the smallest positive number divisible by both inputs. For 4 and 6 it is 12. This is useful when looking for a common interval between repeating whole-number cycles.
Reduce a fraction with the GCD
For 18/30, the common divisor is six. Dividing numerator and denominator by six gives 3/5. Both must be divided by the same factor; changing only the denominator changes the value.
Keep the cycle assumptions explicit
A common multiple can describe ideal repeats with fixed intervals and a shared starting point. Real schedules may have weekends, exceptions or different starting times. Arithmetic alone does not account for those changes.
Put it into practice
Ratio Simplifier & Split Calculator
Simplify a whole-number ratio and divide a total into two proportional shares.
Numbers & textFraction Calculator
Add, subtract, multiply or divide two fractions and reduce the answer to lowest terms.
Numbers & textGCD & LCM Calculator
Find the greatest common divisor and least common multiple of two positive integers.
Numbers & text