Natural Log in Excel

Finding natural logarithms may seem daunting. But it’s easy when you use Excel. Let’s learn how to calculate natural log (LN) with Microsoft Excel.

You may have a list of existing numbers, and want to find the natural log of each one. Or, you may want to perform the calculation in a single cell on data that you input. We’ll explore both ways.

Find Natural Log for Existing Data

Suppose you have a list of five numbers, for which you need to calculate the natural logarithm. These five values are listed in cells A1, A2, A3, A4, and A5.

Begin by clicking into cell B1. Type an = sign to begin a formula. (Hint: each and every formula in Excel begins with an = sign).

Then, type LN, followed immediately by (. Then, click into cell A1, and you’ll see that cell reference populate into the Formula bar. Type ), and then press Enter.

The LN value will calculate.

Now, thanks to Excel’s powerful features, there’s no need to type formulas again. With cell B1 selected, click and hold in the lower right corner of the cell when you see the + symbol appear.

Then, drag down through cells B2, B3, B4, and B5. Excel will automatically update your formula and return the natural log for each individual Column A value.

Find Natural Log of Any Number

In another scenario, you have no data in your cell. Someone may ask you what the LN of 100 is, for example. This is easy to calculate, and very similar to the steps above.

Click into any empty cell, and type the following formula:

=LN(100)

Then press Enter. Notice that the only difference from the prior steps is that there is no cell reference (such as A1) in your formula. This just tells Excel to perform the calculation on the value 100, rather than on existing cell data.

Once again, your solution value appears in the cell where you entered the formula. Excel makes complex math equations easy with built-in features. With a few keystrokes, you’re performing advanced calculations fast.