GCF and LCM of 16 and 24

The GCF of 16 and 24 is 8. The LCM of 16 and 24 is 48.

Method 1: list the factors (GCF)

Factors of 16: 1, 2, 4, 8, 16.
Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24.
Common factors: 1, 2, 4 and 8. The greatest of these is 8.

Method 2: prime factorization

16 = 2 × 2 × 2 × 2
24 = 2 × 2 × 2 × 3

GCF: multiply the prime factors both numbers share: 2 × 2 × 2 = 8.

LCM: multiply every prime the maximum number of times it appears in either number: 2 × 2 × 2 × 2 × 3 = 48.

Method 3: Euclidean algorithm (GCF)

Divide the larger number by the smaller and repeat with the remainder until it is 0. The last non-zero remainder is the GCF.

  1. 24 = 1 × 16 + 8
  2. 16 = 2 × 8 + 0

The last non-zero remainder is 8, so GCF(16, 24) = 8.

LCM by listing multiples

Multiples of 16: 16, 32, 48, 64, ...
Multiples of 24: 24, 48, 72, ...
The first number in both lists is 48.

Check: GCF × LCM = product

8 × 48 = 384 = 16 × 24. This always holds for two numbers, so you can find the LCM as (16 × 24) ÷ 8 = 48.

Simplifying the fraction 16/24

Divide the top and bottom by the GCF 8: 16/24 = 2/3.

GCF and LCM of similar pairs

NumbersGCFLCM
2 and 16216
3 and 16148
4 and 16416
5 and 16180
6 and 16248
7 and 161112
2 and 24224
3 and 24324
4 and 24424
5 and 241120
6 and 24624
7 and 241168

See also: factors of 16 · factors of 24.

Different numbers? Use the GCF and LCM calculator (any amount of numbers) or browse all GCF and LCM pairs.