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Free online LCM calculator to find the least common multiple of 2, 3, or more numbers instantly. Calculate LCM with step-by-step solutions using prime factorization method.
The Least Common Multiple (LCM) of two or more numbers is the smallest positive integer that is divisible by all the given numbers without leaving a remainder. It's also known as the Lowest Common Multiple or Least Common Denominator (LCD) when working with fractions.
For example, the LCM of 4 and 6 is 12 because:
LCM is essential in mathematics for adding and subtracting fractions with different denominators, solving problems involving repeating events, and various real-world applications in scheduling, music, and engineering.
Find the prime factors of each number and multiply the highest powers of all prime factors.
LCM(a, b) = (a × b) / GCF(a, b)
List multiples of each number until you find the smallest common one.
Divide the numbers by common prime factors until no common factors remain, then multiply all divisors and remaining numbers.
For any two numbers a and b:
Example: LCM(12, 18) × GCF(12, 18) = 36 × 6 = 216 = 12 × 18 ✓
Finding when events that repeat at different intervals occur together. Bus schedules, meeting times, shift rotations.
Adding fractions requires common denominator (LCM). Recipe scaling for different serving sizes.
Musical rhythms and beats use LCM to find when patterns align. Audio engineering for synchronizing frequencies.
Synchronizing machines with different cycle times. Packaging items in different quantities.
Tile patterns and floor layouts. Finding common measurements for materials and spacing.
Timing traffic light cycles at intersections. Coordinating signal patterns for traffic flow.
Find greatest common factor
Add, subtract, multiply fractions
Find factors of numbers
Advanced math operations
Calculate percentages easily
Simplify and calculate ratios
Calculate powers and exponents
Square root, cube root calculator
Comprehensive lessons on least common multiple with practice problems
Visit Khan Academy →Mathematical definitions and properties of least common multiple
Visit MathWorld →Easy-to-understand explanations with examples and interactive tools
Visit Math is Fun →Detailed tutorials on finding LCM and its relationship with GCF
Visit Purplemath →Unlike basic calculators limited to 2 numbers, we support LCM calculation for 2, 3, 4, or more numbers simultaneously.
See detailed prime factorization for each number and understand how the LCM is calculated step-by-step.
Add or remove numbers easily with our flexible interface. No fixed limit on how many numbers you can calculate.
One-click access to common LCM problems for faster learning and testing with preset values.
Comprehensive FAQs, multiple calculation methods, and real-world applications to deepen understanding.
Clear explanation of the difference and relationship between LCM and GCF with examples.
Built-in reference table of common LCM calculations for quick lookup and verification.
No ads, no sign-up, no limitations. Completely free with unlimited calculations for students and professionals.