Find the least common multiple of integers

For two numbers, LCM = |a × b| / GCF(a, b). For more than two, the engine folds: LCM(a, b, c) = LCM(LCM(a, b), c). Zeros are refused (every multiple of 0 is 0, which is not a positive LCM here).

LCM(a, b) = |a × b| / GCF(a, b)

LCM(a, b, c) = LCM(LCM(a, b), c)

The identity LCM × GCF = |a × b| for two integers is the implementation, not a prime-factor listing. Intermediate products can grow quickly; very large inputs may overflow floating-point integers. Signs are ignored; the LCM is returned positive.

Integers

At least two nonzero integers. Decimals are refused.

Assumptions

• Positive LCM of nonzero integers.
• Folding pairwise is associative for this operation.

Limits

• Does not print a prime-factor table.
• Huge products may lose integer exactness in JavaScript.

72 is the smallest positive number that 12, 18, and 24 all divide. For adding 1/12 + 1/18, a common denominator can be 72 (or 36 for just those two). The GCF of the same list is 6, not 72.

• Taking the product 12 × 18 × 24 as the LCM.

  The product is a common multiple, not the least. Divide out shared factors via the GCF identity.

• Using the GCF when you needed a common multiple.

  GCF 6 does not work as a common denominator for 1/12 and 1/18.

• GCF (GCD)Enter at least two integers. The result is the largest positive integer that divides all of them — the same GCF used to reduce a fraction or a ratio.
• FractionsTwo integer fractions and an operation. The engine uses a common denominator or cross-products, then reduces by the GCF so the answer is in lowest terms.
• ExponentEvaluate aᵇ. Integers, decimals, negative exponents (reciprocals), and 1/2 (square root, base ≥ 0) are possible, within the reals and floating-point limits.
• Square rootEnter a number that is not negative. The tool returns the principal (nonnegative) square root. It is the inverse of squaring, not a cube root or an nth root.
• RatioTwo integers in, a reduced ratio out (8 : 12 becomes 2 : 3), plus the quotient A/B and each term’s weight in the sum of absolute values — not “A as a percent of B.”
• Speed, distance, timeTwo known quantities, the third follows. Kilometres and km/h, or miles and mph, but not a mix of the two systems.

Written by Rédaction HexaCalc (editorial team). Content last updated: August 25, 2026. No third-party medical or financial review is claimed.

• Les Éléments, Livre I (théorème de Pythagore) et Livre VII (algorithme d’Euclide) — Tradition mathématique euclidienne