LCM of 20 and 30
The least common multiple of 20 and 30 is 60 — the smallest positive number into which both 20 and 30 divide evenly. This page lists the first twelve common multiples of the pair, which are exactly the multiples of 60.
20 and 30 share the factor 10, so their first meeting point comes earlier than the raw product: the LCM is (20 × 30) ÷ 10 = 600 ÷ 10 = 60. Both numbers divide it exactly — 20 fits 3 times and 30 fits 2 times — and the pairing identity LCM × GCF = a × b holds again: 60 × 10 = 600. After 60, the lines re-synchronize for good, so the common multiples continue 120, 180, 240, and onward.
| # | Common multiple |
|---|---|
| 1 | 60 |
| 2 | 120 |
| 3 | 180 |
| 4 | 240 |
| 5 | 300 |
| 6 | 360 |
| 7 | 420 |
| 8 | 480 |
| 9 | 540 |
| 10 | 600 |
| 11 | 660 |
| 12 | 720 |
Frequently asked questions
What is the LCM of 20 and 30?
The least common multiple of 20 and 30 is 60. The multiples of 20 begin 20, 40, 60, 80, … and the multiples of 30 begin 30, 60, 90, …, and 60 is the first value both lists share. Formula check: (20 × 30) ÷ GCF(20, 30) = 600 ÷ 10 = 60.
How do you find the LCM of 20 and 30?
Compare prime factorizations: 20 = 2² × 5 and 30 = 2 × 3 × 5. Carry every prime at its highest power into the answer: 2² × 3 × 5 = 60. The shortcut through the GCF lands on the same value: (20 × 30) ÷ 10 = 60.
What is the GCF of 20 and 30?
10. The largest number dividing both. The identity GCF × LCM = 20 × 30 checks it against this page: 10 × 60 = 600. The same GCF reduces fractions built on 20 and 30, while 60 is the common denominator that needs no reducing.
What are the common multiples of 20 and 30?
Exactly the multiples of the LCM: 60, 120, 180, 240, 300, 360, and onward without end. The table above lists the first twelve; every later one is another 60 steps out. These are the numbers into which both 20 and 30 divide evenly — which is why the LCM itself is the natural common denominator in fraction work.