Contents

Microsoft Excel has a large number of functions that allow you to quickly perform mathematical calculations. One of the most common and popular functions is LOG, which can be used to calculate logarithms. This article will discuss the principle of its operation and characteristic features.

## How to calculate logarithm in Excel

LOG allows you to read the logarithm of a number to the specified base. **In general, the formula for the logarithm in Excel, regardless of the version of the program, is written as follows: =LOG(number;[base]). **There are two arguments in the presented formula:

- Number. This is the numeric value entered by the user from which the logarithm is to be calculated. The number can be entered manually in the formula input field, or you can point the mouse cursor to the desired cell with the written value.
- Base. This is one of the components of the logarithm by which it is calculated. The base can also be written as a number.

Pay attention!If the base of the logarithm is not filled in Excel, the program will automatically set the value to zero.

## How to calculate decimal logarithm in Microsoft Excel

For ease of calculation, Excel has a separate function that calculates only decimal logarithms – this is LOG10. This formula sets the base to 10. After selecting the LOG10 function, the user will only need to enter the number from which the logarithm will be calculated, and the base is automatically set to 10. **The formula entry looks like this: =LOG10(number).**

## How to use logarithmic function in Excel

Regardless of the software version installed on the computer, the calculation of logarithms is divided into several stages:

- Launch Excel and create a small two-column table.
- Write any seven numbers in the first column. Their number is chosen at the discretion of the user. The second column will display the values of the logarithms of numerical values.

- Click LMB on the number in the first column to select it.
- Find the math function icon on the left side of the formula bar and click on it. This action means “Insert Function”.

- After performing the previous manipulation, the “Insert function” window will be displayed. Here you need to expand the “Category” column by clicking on the arrow on the right, select the “Math” option from the list and click on “OK”.
- In the list of operators that opens, click on the “LOG” line, and then click on “OK” to confirm the action. The logarithmic formula settings menu should now be displayed.

- Specify the data for the calculation. In the “Number” field, you need to write a numerical value from which the logarithm will be calculated by clicking on the corresponding cell in the created table, and in the “Base” line, in this case, you will need to enter the number 3.

- Press “Enter” or “OK” at the bottom of the window and check the result. If the actions are performed correctly, then the result of calculating the logarithm will be displayed in the previously selected cell of the table. If you click on this number, then a calculation formula will appear in the line above.

- Do the same operation with the remaining numbers in the table to calculate their logarithm.

Additional Information!In Excel, it is not necessary to manually calculate the logarithm of each number. To simplify calculations and save time, you need to move the mouse pointer over the cross in the lower right corner of the cell with the calculated value, hold down LMB and drag the formula to the remaining lines of the table so that they are filled in automatically. Moreover, the desired formula will be written for each number.

## Using the LOG10 statement in Excel

Based on the example discussed above, you can study the operation of the LOG10 function. To simplify the task, let’s leave the table with the same numbers, after deleting the previously calculated logarithms in the second column. The principle of operation of the LOG10 operator can be described as follows:

- Select the first cell in the second column of the table and click on the “Insert function” button on the left of the line to enter formulas.
- According to the scheme discussed above, indicate the category “Mathematics”, select the function “LOG10” and click on “Enter” or click on “OK” at the bottom of the “Insert function” window.
- In the “Function Arguments” menu that opens, you need to enter only a numerical value, according to which the logarithm will be performed. In this field, you must specify a reference to a cell with a number in the source table.

- Press “OK” or “Enter” and check the result. In the second column, the logarithm of the specified numerical value should be calculated.
- Similarly, stretch the calculated value to the remaining rows in the table.

Important!When setting up logarithms in Excel, in the “Number” field, you can manually write the desired numbers from the table.

## Alternative Method to Calculate Logarithms in Excel

Microsoft Office Excel has an easier way to calculate the logarithms of certain numbers. It helps to save the time required to perform a mathematical operation. This calculation method is divided into the following steps:

- In a free cell of the program, write the number 100. You can specify any other value, it does not matter.
- Select another free cell with the mouse cursor.
- Move to the formula bar at the top of the main program menu.
- Prescribe the formula
*“=**LOG**(number;[base])*” and press “Enter”. In this example, after opening the bracket, select with the mouse the cell in which the number 100 is written, then put a semicolon and indicate the base, for example 10. Next, close the bracket and click on “Enter” to complete the formula. The value will be calculated automatically.

Pay attention!A quick calculation of decimal logarithms is performed similarly using the LOG10 operator.

## Conclusion

Thus, in Excel, algorithms are calculated using the “LOG” and “LOG10” functions in the shortest possible time. The calculation methods were described in detail above, so that each user will be able to choose the most comfortable option for himself.