How to Find the Greatest Common Divisor with GCD

GCD finds the largest number that divides all your values — for identical gift bags, tile sizes and simplified ratios.

You will learn to

• Find the most identical bags for two items
• Extend GCD to a whole range
• Simplify a ratio like 1920:1080 to 16:9

How it works

GCD(number1, [number2], …) returns the greatest common divisor — the largest whole number that divides every value exactly. With 48 apples and 72 granola bars, =GCD(48,72) is 24, so you can make 24 identical bags with 2 apples and 3 bars in each.

GCD accepts ranges and up to 255 values. It is also how you reduce a ratio: divide both sides by their GCD, so 1920:1080 becomes 16:9. Decimals are truncated before the calculation, and negative values return #NUM!.

=GCD(B2:B5)