A to Z of Excel Functions: The LOG10 Function

Welcome back to our regular A to Z of Excel Functions blog. Today we look at the LOG10 function.

The LOG10 function

For a given base, a logarithm states the power that the base must be raised to for a given number, e.g.

10 = 10 = 10¹ ⇔ log₁₀10 = 1

100 = 10 x 10 = 10² ⇔ log₁₀100 = 2

1,000 = 10 x 10 x 10 = 10³ ⇔ log₁₀1,000 = 3

1 = 10⁰ ⇔ log₁₀1 = 0

0.1 =  = 10^-1 ⇔ log₁₀0.1 = -1

0.01 =  x  = 10^-2 ⇔ log₁₀0.01 = -2

Therefore,

 y = a^b ⇔ log_ay = b

 = a^b-c ⇔ log_ay = b – c

y = a^b.a^c ⇔ log_ay = b + c

y = cⁿ ⇔ log_acⁿ = nlog_ac.

The LOG10 function is not the ninth sequel of the LOG function, but rather it returns the base 10 logarithm of a number you specify.  Its syntax is given by

The LOG10 function has the following argument:

• number: this is required and represents the positive real number for which you wish to determine the base 10 logarithm.

Please see my example below:

We’ll continue our A to Z of Excel Functions soon. Keep checking back – there’s a new blog post every business day.

A full page of the function articles can be found here.