LOG10 function

The LOG10 function in Excel returns the base-10 logarithm (common logarithm) of a number.

Syntax

=LOG10(number)

Parameters

• number: The positive real number for which you want to calculate the logarithm. This value must be greater than 0.

Return Value

The function returns the base-10 logarithm of the given number.

Example Usage

Example 1: Base-10 Logarithm of 1000

=LOG10(1000)

Result: 3

Explanation: The logarithm of 1000 with base 10 is 3 because $10^3 = 1000$.

Example 2: Base-10 Logarithm of 100

=LOG10(100)

Result: 2

Explanation: The logarithm of 100 with base 10 is 2 because $10^2 = 100$.

Example 3: Base-10 Logarithm of 1

=LOG10(1)

Result: 0

Explanation: The logarithm of 1 with base 10 is 0 because $10^0 = 1$.

Example 4: Using a Cell Reference

=LOG10(A1)

If cell A1 contains the value 10000, the result will be the logarithm of 10000 with base 10, which is 4 because $10^4 = 10000$.

Important Notes

• Input Range: The number argument must be greater than 0. If it’s less than or equal to 0, Excel will return a #NUM! error.
• Common Logarithm: LOG10 is a special case of the LOG function, where the base is always 10. It’s used for calculations involving powers of 10 or scaling large numbers.

This function is useful when working with scientific and engineering data where logarithmic scales are frequently used.