LCM Calculator

What is the LCM Calculator?

Find the least common multiple of two or more whole numbers. The least common multiple is the smallest number every value in a list divides into, which helps find common denominators and repeating schedules.

How to use the LCM Calculator

1. Enter your numbers.
2. Results update automatically as you type; you can also press Calculate.
3. Read the output: least common multiple, greatest common divisor.
4. Use the 📊 chart to see the result visually, then copy or share it.

Formula and method

Worked example

With numbers = 4, 6, 15, the LCM Calculator returns least common multiple: 60; greatest common divisor: 1.

Where the LCM Calculator helps in real life

Two bus routes leave the same stop every 12 and 18 minutes. The LCM of 36 tells you they depart together every 36 minutes.

A student is adding 5/12 and 7/18. The LCM of 36 gives the common denominator needed before adding.

Common mistakes to avoid

• Confusing the least common multiple with the greatest common divisor.
• Multiplying the numbers together, which gives a common multiple but rarely the smallest.
• Entering decimals instead of whole numbers.
• Forgetting to include every number in the list.

💡 Practical tip: For two numbers, LCM × GCD equals the product of the numbers — a handy check.

Tips for better results

• Use the LCM as the lowest common denominator for fractions.
• Use it to find when repeating events coincide.
• Pair it with the GCD calculator to simplify the final answer.

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