LCM for 28 and 40

What's the Least Common Multiple (LCM) of 28 and 40?

Answer: LCM of 28 and 40 is 280

(Two hundred eighty)

Finding LCM for 28 and 40 using GCF's of these numbers

The first method to find LCM for numbers 28 and 40 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:

LCM = (Number1 × Number2) ÷ GCF

GCF of numbers 28 and 40 is 4, so

LCM = (28 × 40) ÷ 4

LCM = 1120 ÷ 4

LCM = 280

Finding LCM for 28 and 40 by Listing Multiples

The second method to find LCM for numbers 28 and 40 is to list out the common multiples for both nubmers and pick the first which matching:

Multiples of 28: 28, 56, 84, 112, 140, 168, 196, 224, 252, 280, 308, 336

Multiples of 40: 40, 80, 120, 160, 200, 240, 280, 320, 360

So the LCM for 28 and 40 is 280

Finding LCM for 28 and 40 by Prime Factorization

Another method to find LCM for numbers 28 and 40 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:

All Prime Factors of 28: 2, 2, 7 (exponent form: 22, 71)

All Prime Factors of 40: 2, 2, 2, 5 (exponent form: 23, 51)

23 × 71 × 51 = 280

See Also

About "Least Common Multiple" Calculator

This calculator will help you find the Least Common Multiple (LCM) of two numbers. For example, it can help you find out what's the Least Common Multiple (LCM) of 28 and 40? (The answer is: 280). Select the first number (e.g. '28') and the second number (e.g. '40'). After that hit the 'Calculate' button.
Least Common Multiple (LCM) also known as the Lowest Common Multiple or Smallest Common Multiple of 2 numbers - it is the smallest positive integer that is divisible by both numbers

LCM Table

Number 1Number 2LCM
1340520
1440280
1540
1640
1740680
1840
1940760
2040
2140840
2240440
2340920
2440
2540
2640520
27401080
2840
29401160
3040
31401240
3240
33401320
3440680
3540
3640
37401480
3840760
39401560
404040
41401640
4240840

FAQ

What's the Least Common Multiple (LCM) of 28 and 40?

LCM of 28 and 40 is 280