In this post, we learned the behavior of natural logarithm and the usage of LN formula. While we can agree that the logarithm evaluated upon base e is quite useful in many fields, it isn’t as flexible. For instance, we can not evaluate the logarithm for a base that is not, the Euler’s number (e). What if we need logarithm value for the base of 2? Or base of 10? In such scenarios, the LOG formula in Google Sheets can help us evaluate values for any base that we choose.

If we were to plot graphs of logarithm functions evaluated upon base 2 and 10, this is how they would look. You can also compare them against the natural logarithm (base e) curve.

Log formula in Google Sheets - Graphs

Logarithm functions for bases 2, e, and 10. [Image Source: Wikipedia]

Syntax

LOG(value, base)

  • value – The value for which to calculate the logarithm given base.
  • base – The base to use for calculation of the logarithm.

It is important to note that the inputs for value and base parameters must be positive numeric values. The formula will return a #NUM! error, if we tried to use it with a zero or negative value and/or base.

Usage: LOG formula in Google Sheets

Since this is a mathematical function, it gives us more perspective if we applied this practically on the Google Sheets application. So, here we go.

LOG formula in Google Sheets

We tried using the base of 10 across all the examples. As it is the case with most Google Sheets formulas, the LOG formula also accepts direct numeric values, as well as cell references. We demonstrated that in our examples.

We will notice that the values tend to progress in line with the curve corresponding to base 10 in the graph. A better way to visualize and reinforce our understanding would be to plot graphs of multiple bases. Now that we already have the outputs for base 10, let’s try doing the same exercise for bases 2 and e.

LOG formula in Google Sheets

If we now plot these values on a chart, it will look like this. And unsurprisingly, it resembles the very first graph on this post.

LOG formula in Google Sheets