Example 1
- a = 6
- b = 8
24
24 is divisible by 6 and 8 - no smaller positive common multiple exists.
LCM calculator
Type two integers. LCM, the least common multiple, is the smallest positive number divisible by both. LCM(6, 8) = 24. LCM(4, 6) = 12, a common denominator for 1/4 and 1/6.
The LCM is computed for integers. When one number is zero, this tool treats the LCM as 0.
Result
Enter two whole numbers.
How does it work?
LCM (least common multiple) is the smallest positive integer divisible by both given numbers. LCM(6, 8) = 24: 24 ÷ 6 = 4 and 24 ÷ 8 = 3, and 12 is not divisible by 8. LCM(4, 6) = 12. LCM(7, 5) = 35, because when GCD = 1 the multiple is just the product.
You can get it from GCD, the greatest common divisor: LCM(a, b) = |a × b| ÷ GCD(a, b). For 6 and 8: GCD = 2, 48 ÷ 2 = 24. For 12 and 18: GCD = 6, 216 ÷ 6 = 36. If one number is zero, the calculator uses LCM as 0.
The fields are First number and Second number, integers only. Type 6 and 8, click Calculate. A fraction does not run. A minus does not break it: LCM looks at absolute values.
It helps with a common denominator: 1/6 + 1/8 needs 24. GCD reduces a numerator and a denominator; LCM makes them meet. Two cycles every 6 and every 8 days meet again on day 24.
Without both integers, nothing computes. 6 and 8 still give 24 no matter the header units.
LCM(12, 18) = 36, LCM(84, 36) = 252, LCM(144, 96) = 288. Check 6 and 8 on the page first.
Formula
LCM(a, b) = |a × b| ÷ GCD(a, b)
How to use
- Type the first integer, for example 6.
- Type the second integer, for example 8.
- Click Calculate. LCM(6, 8) = 24. LCM(4, 6) = 12.
- A fraction does not run. Zero with another number gives LCM = 0 in this calculator.
- Reducing a fraction lives on GCD. Here you stay with a common multiple and a common denominator.
LCM(6, 8) = 24
The least common multiple. LCM(6, 8) = 24. LCM(4, 6) = 12, a common denominator for 1/4 and 1/6.
- LCM
- The smallest positive number divisible by both. LCM(6, 8) = 24. LCM(7, 5) = 35, the product when GCD = 1.
- GCD
- It enters LCM = |a·b| / GCD. When GCD(7, 5) = 1, LCM is 35. The calculator still prints the multiple, not the divisor alone.
- a
- First integer. 6 with b = 8 gives 24. 12 with 18 gives 36.
Examples
Example 2
- a = 4
- b = 6
12
A common denominator for 1/4 and 1/6 can be 12.
Example 3
- a = 7
- b = 5
35
When GCD = 1, the LCM is simply the product: 7 × 5 = 35.
Example 4
- a = 12
- b = 18
36
36 is the smallest number divisible by 12 and 18.
Example 5
- First number: 12
- Second number: 18
216 and GCD is
Does LCM(12, 18) equal 36? 216 and GCD is.
Example 6
- First number: 84
- Second number: 36
252
What is the LCM of 84 and 36? 252.
Example 7
- First number: 144
- Second number: 96
288
What is the LCM of 144 and 96? 288.
Example 8
- First number: 270
- Second number: 192
8640
What is the LCM of 270 and 192? 8640.
Related calculators
Frequently asked questions
What is LCM(6, 8)?
The least common multiple is 24. That number is divisible by 6 and by 8, and twelve drops out because 12 is not divisible by 8.
What does LCM mean?
LCM is the least common multiple. You want the smallest positive integer that both of the numbers you typed can divide.
What is LCM(4, 6)?
It comes out 12. That is also a common denominator, where 1/4 becomes 3/12 and 1/6 becomes 2/12.
How does LCM use GCD?
The formula is LCM(a, b) = |a × b| ÷ GCD(a, b). For 6 and 8 the GCD is 2, then 48 divided by 2 gives 24.
What is LCM(7, 5)?
The LCM is 35. Their GCD is 1, so the least common multiple is simply the product 7 × 5.
What is LCM(12, 18)?
The result is 36, because GCD(12, 18) = 6 and 216÷6 = 36. On the page LCM(84, 36) gives 252 the same way.
How is LCM different from GCD?
GCD(6, 8) = 2 divides both numbers. LCM = 24 is divisible by both. Two different questions, two cards.
What if one number is 0?
This calculator treats the LCM as 0. Zero and zero also do not build a positive common multiple.
Will 6.5 and 8 run?
No. LCM, like GCD, is for integers. Type 6 and 8, not 6.5.
Why LCM for 1/6 + 1/8?
The common denominator 24 lets you add 4/24 + 3/24. GCD reduces a fraction, but it does not find where the denominators meet.
Knowledge sources
The calculator computes the same formula as the definition below.
Page updated in 2026.