A walkthrough, end to end.
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Enter two or more integers separated by commas, spaces, or newlines.
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The calculator returns the least common multiple via LCM(a, b) = |a × b| / GCD(a, b).
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Useful for adding fractions and finding common cycle times.
LCM via GCD
LCM(a, b) = |a × b| / GCD(a, b). For lists, reduce pairwise. Faster than testing multiples; works for any positive integers.
What you can do with this.
Adding fractions (common denominator)
1/4 + 1/6 needs LCD = LCM(4, 6) = 12. Convert: 3/12 + 2/12 = 5/12. The calculator gives the LCD directly.
Scheduling cycles
Three jobs run every 4, 6, and 8 hours. They all align at LCM(4,6,8) = 24 hours = once per day. Useful for coordination.
Gear / pulley alignment
Two gears with 12 and 18 teeth align every LCM(12, 18) = 36 teeth, equivalent to 3 revolutions of the small gear and 2 of the large.
Music meter
Two musical phrases of 6 beats and 8 beats coincide every LCM(6, 8) = 24 beats. Useful for polyrhythm and complex meters.
Gear ratio simplification
Inverse of LCM is GCD; both useful in mechanics. Use the LCM Calculator for cycle alignment, GCF Calculator for ratio simplification.
Pattern repetition
Two patterns of length 5 and 7 repeat together every LCM(5, 7) = 35. For coprime values, LCM = product. The calculator confirms automatically.
Math homework: LCM problems
Standard middle school topic. Helpful for fractions, factoring, and word problems involving repeating events.
LCM 2026 — what's current
Foundational number theory, unchanged. Calculator wins for speed and verification on big inputs.
Frequently asked.
Same thing — LCD (Lowest Common Denominator) when used in fraction context; LCM (Least Common Multiple) generally. Identical math.
LCM with zero is undefined or zero by convention. The calculator filters zeros from input.
LCM uses absolute values. Negatives are accepted but the result is positive.
No. Calculations run entirely in your browser.