GCF and LCM of 7 and 14

The GCF of 7 and 14 is 7. The LCM of 7 and 14 is 14.

Method 1: list the factors (GCF)

Factors of 7: 1, 7.
Factors of 14: 1, 2, 7, 14.
Common factors: 1 and 7. The greatest of these is 7.

Method 2: prime factorization

7 = 7 (prime)
14 = 2 × 7

GCF: multiply the prime factors both numbers share: 7 = 7.

LCM: multiply every prime the maximum number of times it appears in either number: 2 × 7 = 14.

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. 14 = 2 × 7 + 0

The last non-zero remainder is 7, so GCF(7, 14) = 7.

LCM by listing multiples

Multiples of 7: 7, 14, 21, ...
Multiples of 14: 14, 28, ...
The first number in both lists is 14.

Check: GCF × LCM = product

7 × 14 = 98 = 7 × 14. This always holds for two numbers, so you can find the LCM as (7 × 14) ÷ 7 = 14.

Simplifying the fraction 7/14

Divide the top and bottom by the GCF 7: 7/14 = 1/2.

GCF and LCM of similar pairs

NumbersGCFLCM
2 and 7114
3 and 7121
4 and 7128
5 and 7135
6 and 7142
7 and 8156
2 and 14214
3 and 14142
4 and 14228
5 and 14170
6 and 14242
8 and 14256

See also: factors of 7 · factors of 14 · 7/14 as a decimal.

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