LCM for 18 and 15

What's the Least Common Multiple (LCM) of 18 and 15?

Answer: LCM of 18 and 15 is 90

(Ninety)

Finding LCM for 18 and 15 using GCF's of these numbers

The first method to find LCM for numbers 18 and 15 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:

LCM = (Number1 × Number2) ÷ GCF

GCF of numbers 18 and 15 is 3, so

LCM = (18 × 15) ÷ 3

LCM = 270 ÷ 3

LCM = 90

Finding LCM for 18 and 15 by Listing Multiples

The second method to find LCM for numbers 18 and 15 is to list out the common multiples for both nubmers and pick the first which matching:

Multiples of 18: 18, 36, 54, 72, 90, 108, 126

Multiples of 15: 15, 30, 45, 60, 75, 90, 105, 120

So the LCM for 18 and 15 is 90

Finding LCM for 18 and 15 by Prime Factorization

Another method to find LCM for numbers 18 and 15 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:

All Prime Factors of 18: 2, 3, 3 (exponent form: 21, 32)

All Prime Factors of 15: 3, 5 (exponent form: 31, 51)

21 × 32 × 51 = 90

LCM Table

Number 1Number 2LCM
315
415
515
615
715
815
915
1015
1115165
1215
1315
1415
151515
1615240
1715255
1815
1915285
2015
2115105
2215330
2315345
2415120
2515
2615390
2715135
2815420
2915435
301530
3115465
3215480

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 18 and 15? (The answer is: 90). Select the first number (e.g. '18') and the second number (e.g. '15'). 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

FAQ

What's the Least Common Multiple (LCM) of 18 and 15?

LCM of 18 and 15 is 90