LCM Function in Excel
Calculate least common multiples in Excel and Sheets with the LCM function. Learn syntax, examples, and use cases for scheduling and patterns.
Excel
Google SheetsExcelGoogle Sheets=LCM(number1, [number2], ...)Quick Answer
Function LCM function calculates the least common multiple of two or more numbers in Excel and Google Sheets. It returns the smallest positive integer that is evenly divisible by all specified numbers. Commonly used for scheduling, pattern analysis, and finding when recurring events align.
Practical Examples
Basic LCM Calculation
Calculate the least common multiple of two numbers to find when two events that occur every 6 and 8 days will happen on the same day.
Multiple Number LCM
Find LCM of three or more numbers for complex scheduling scenarios involving multiple machines requiring maintenance at different intervals.
LCM with Cell Ranges
Calculate LCM from a range of cells containing delivery frequencies for a distribution center with multiple routes.
LCM for Fraction Common Denominator
Using LCM to find common denominators for fraction operations in budget allocation scenarios.
Dynamic LCM with Error Handling
Production-ready formula with validation and error handling for employee shift rotation systems.
Common Errors and Solutions
LCM returns #NUM! error
Occurs when any input value is less than or equal to zero, or when the result exceeds Excel's calculation limit (2^53 = 9,007,199,254,740,992)
See solution details above
To prevent this error: 1) Use data validation to restrict inputs to positive integers: Data > Data Validation > Whole number > greater than 0, 2) Add IF statements to check for valid ranges before calculation: =IF(AND(MIN(A2:A10)>0, COUNTA(A2:A10)=ROWS(A2:A10)), LCM(A2:A10), "Invalid Input"), 3) In Excel 365, filter out blank cells using FILTER function: =LCM(FILTER(A2:A10, A2:A10<>""))
Example:
LCM returns #VALUE! error
Input contains non-numeric values like text, dates formatted as text, or logical values (TRUE/FALSE) that cannot be converted to numbers
See solution details above
To prevent this error: 1) Apply proper number formatting to input cells before entering data, 2) Use data validation to allow only numeric entries: Data > Data Validation > Custom > =ISNUMBER(A1), 3) Clean imported data with TRIM and VALUE functions: =VALUE(TRIM(A1)), 4) Check data types after import using the ISNUMBER function
Example:
LCM returns #NAME? error
Excel doesn't recognize the LCM function, typically in Excel versions before 2003 or when Analysis ToolPak is not enabled (in older versions)
See solution details above
To prevent this error: 1) Verify Excel version compatibility before creating formulas with LCM, 2) Document add-in requirements for shared workbooks in README files, 3) Use Excel's compatibility checker before sharing: File > Info > Check for Issues, 4) Consider using Excel Online or Google Sheets for guaranteed compatibility
Advanced Tips and Best Practices
Combine LCM with GCD for Fraction Simplification
Use LCM to find common denominators and GCD to reduce fractions to simplest form. The two functions are mathematically related: LCM(a,b) = (a × b) / GCD(a,b). This relationship is invaluable for financial calculations involving fractions, percentages, and ratios. For example, when adding fractions, first use LCM to find the common denominator, perform the addition, then use GCD to simplify the result.
Use with DATE Functions for Scheduling
Combine LCM with DATE, TODAY, and MOD functions to calculate future dates when multiple recurring events will align. This creates powerful automated scheduling tools. The pattern =TODAY()+LCM(period1,period2)-MOD(TODAY(),LCM(period1,period2)) calculates the next date when two events will coincide, accounting for today's date and the cycle alignment.
Array Formula for Dynamic Ranges
In Excel 365 and Google Sheets, use LCM with dynamic array functions like FILTER, UNIQUE, or SORT to automatically adjust calculations when source data changes. This creates self-updating schedules and planning tools that adapt to changing business conditions. The formula =LCM(FILTER(A2:A100, B2:B100="Active")) will recalculate automatically whenever the active status changes.
Watch for Calculation Limits with Large Numbers
LCM results can grow exponentially, especially with prime numbers or numbers sharing few common factors. Excel's maximum value is 2^53 (approximately 9.007 quadrillion). With prime numbers, the LCM equals their product, which can quickly exceed limits. For example, LCM(97, 101, 103) = 1,009,091 (product of three primes). Always validate that your result makes practical sense for your business context.
Cross-Platform Compatibility
The LCM function works identically in Excel (Windows/Mac), Google Sheets, and Excel Online with no syntax differences. This makes it completely safe to use in collaborative workbooks without worrying about compatibility issues when sharing files across platforms or with team members using different tools. The function produces identical results regardless of platform.
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Example Excel formula:
Related Formulas
The GCD function calculates the greatest common divisor of two or more integers for simplifying fractions and solving mathematical problems.
ExcelSheetsThe MOD function returns the remainder from division. Perfect for determining even/odd numbers, creating patterns, and cycling sequences.
ExcelSheetsThe ABS function returns the absolute value of a number, removing any negative sign. Learn syntax, examples, and common errors with this complete guide.
ExcelSheetsAREAS counts the number of areas (ranges or cells) in a reference, useful for validating complex range selections and non-contiguous data.
ExcelSheets