In Microsoft Excel, a function is a predefined formula that makes calculations using specific values called arguments in a specific order or Structure. In this tutorial, we will explain how to use the **LOG and LOG10 Functions in Excel**. The LOG and the LOG10 functions are both Math and Trigonometry functions. The LOG function returns the logarithm of a number to the base you specify, and the LOG10 returns the base -10 logarithm of a number.

Below are the formulas and syntax of both the LOG and LOG10 functions.

**LOG**

LOG (number, [base])

**Numbe**r: The positive real number for which you want the logarithm. It is required.

**Base**: The base of the logarithm. Optional.

**LOG10**

LOG10 (number)

**Number**: The positive real number for which you want the base-10 logarithm.

## How to use the LOG function in Excel

- Launch
**Microsoft Excel**. - Enter your data or use existing data.
- Type into the cell where you want to place the result
**=LOG (A4, B4)**. - Press Enter to see the result. The result is
**6**. - Now drag the fill handle down to see the other result.
- There are two other methods to use the LOG function.

**Method one** is to click the *fx* button on the top left of the Excel worksheet.

An **Insert Function** dialog box will appear.

Inside the dialog box, in the section **Select a Category**, select *Math and Trigonometry *from the list box.

In the section **Select a Function**, choose the *LOG *function from the list.

Then click *OK.*

*A ***Function Arguments*** *dialog box will open*. *

Type into the entry boxes the cell that contains the number you want to calculate.

Then click *OK*.

**Method two** is to click the **Formulas **tab and click the *Math and Trigonometry *button in the *Function Library* group.

Then select *LOG* from the drop-down menu.

A **Function Arguments** dialog box will open.

Follow the same method in **Method 1**.

Then click *OK*.

## How to use the LOG10 functions in Excel

- Enter your data or use existing data.
- Type into the cell where you want to place the result
*=LOG10(A4)*. - Press Enter to see the result. The result is
*1.653213*. - Now drag the fill handle down to see the other result.
- There are two other methods to use the LOG10 function.
**Method one**is to click the*fx*button on the top left of the Excel worksheet.- An
**Insert Function**dialog box will appear.

Inside the dialog box, in the section **Select a Category**, select Math* and Trigonometry *from the list box.

In the section **Select a Function**, choose the *LOG10 *function from the list.

Then click *OK.*

*A ***Function Arguments*** *dialog box will open*. *

Type into the entry boxes the cell that contains the number you want to calculate.

Then click *OK*.

**Method two** is to click the **Formulas **tab and click the *Math and Trigonometry *button in the *Function Library* group.

Then select *LOG**10* from the drop-down menu.

A **Function Arguments** dialog box will open.

Follow the same method in **Method 1**.

Then click *OK*.

We hope you understand how to use the LOG and LOG10 functions in Microsoft Excel.

### What is the difference between LOG and LOG10 in Excel?

The difference between the LOG and LOG10 functions in Microsoft Excel is that LOG returns the logarithm of a number to the base you specify, and LOG10 returns the base -10 logarithm of a number. In other words, you can specify the number while using LOG function. On the other hand, the base is fixed in LOG10 function.

### What is the difference between log and LN in Excel?

The difference between the LOG and LN functions in Excel is that LOG returns the logarithm of a number to the base you specify, while the LN function returns the natural logarithm of a number. Log and LN are the same terms that are being used in Mathematics in school or college books.