A number system is a systematic way to represent numbers with symbolic characters and uses a base value to conveniently group numbers in compact form. The most common number system is decimal, which has a base value of 10, and a symbolic character set of 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. However, there are other number systems, and they can be more efficient to use for a specific purpose. For example, because computers use Boolean logic to perform calculations and operations, they use the binary number system, which has a base value of 2.
Microsoft Office Excel has several functions that you can use to convert numbers to and from the following number systems:
Number system 
Base value 
Symbolic character set 
Binary 
2 
0,1 
Octal 
8 
0, 1, 2, 3, 4, 5, 6, 7 
Decimal 
10 
0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 
Hexadecimal 
16 
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F 
What do you want to do?
Convert a binary number to decimal
Convert a binary number to hexadecimal
Convert a binary number to octal
Converts a decimal number to binary
Convert a decimal number to hexadecimal
Convert a decimal number to octal
Convert a hexadecimal number to binary
Convert a hexadecimal number to decimal
Convert a hexadecimal number to octal
Convert an octal number to binary
Convert an octal number to decimal
Convert an octal number to hexadecimal
Convert a binary number to decimal
To do this task, use the BIN2DEC function.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

A 
B 
Formula 
Description (Result) 
=BIN2DEC(1100100) 
Converts binary 1100100 to decimal (100) 
=BIN2DEC(1111111111) 
Converts binary 1111111111 to decimal (1) 

Function details
BIN2DEC
Top of Page
Convert a binary number to hexadecimal
To do this task, use the BIN2HEX function.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

A 
B 
Formula 
Description (Result) 
=BIN2HEX(11111011, 4) 
Converts binary 11111011 to hexadecimal with 4 characters (00FB) 
=BIN2HEX(1110) 
Converts binary 1110 to hexadecimal (E) 
=BIN2HEX(1111111111) 
Converts binary 1111111111 to hexadecimal (FFFFFFFFFF) 

Function details
BIN2HEX
Top of Page
Convert a binary number to octal
To do this task, use the BIN2OCT function.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

A 
B 
Formula 
Description (Result) 
=BIN2OCT(1001, 3) 
Converts binary 1001 to octal with 3 characters (011) 
=BIN2OCT(1100100) 
Converts binary 1100100 to octal (144) 
=BIN2OCT(1111111111) 
Converts binary 1111111111 to octal (7777777777) 

Function details
BIN2OCT
Top of Page
Converts a decimal number to binary
To do this task, use the DEC2BIN function.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

A 
B 
Formula 
Description (Result) 
=DEC2BIN(9, 4) 
Converts decimal 9 to binary with 4 characters (1001) 
=DEC2BIN(100) 
Converts decimal 100 to binary (1110011100) 

Function details
DEC2BIN
Top of Page
Convert a decimal number to hexadecimal
To do this task, use the DEC2HEX function.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

A 
B 
Formula 
Description (Result) 
=DEC2HEX(100, 4) 
Converts decimal 100 to hexadecimal with 4 characters (0064) 
=DEC2HEX(54) 
Converts decimal 54 to hexadecimal (FFFFFFFFCA) 

Function details
DEC2HEX
Top of Page
Convert a decimal number to octal
To do this task, use the DEC2OCT function.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

A 
B 
Formula 
Description (Result) 
=DEC2OCT(58, 3) 
Converts decimal 58 to octal (072) 
=DEC2OCT(100) 
Converts decimal to octal (7777777634) 

Function details
DEC2OCT
Top of Page
Convert a hexadecimal number to binary
To do this task, use the HEX2BIN function.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

A 
B 
Formula 
Description (Result) 
=HEX2BIN("F", 8) 
Converts hexadecimal F to binary, with 8 characters (00001111) 
=HEX2BIN("B7") 
Converts hexadecimal B7 to binary (10110111) 
=HEX2BIN("FFFFFFFFFF") 
Converts hexadecimal FFFFFFFFFF to binary (1111111111) 

Function details
HEX2BIN
Top of Page
Convert a hexadecimal number to decimal
To do this task, use the HEX2DEC function.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

A 
B 
Formula 
Description (Result) 
=HEX2DEC("A5") 
Converts hexadecimal A5 to decimal (165) 
=HEX2DEC("FFFFFFFF5B") 
Converts hexadecimal FFFFFFFF5B to decimal (165) 
=HEX2DEC("3DA408B9") 
Converts hexadecimal 3DA408B9 to decimal (1034160313) 

Function details
HEX2DEC
Top of Page
Convert a hexadecimal number to octal
To do this task, use the HEX2OCT function.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

A 
B 
Formula 
Description (Result) 
=HEX2OCT("F", 3) 
Converts hexadecimal F to octal with 3 characters (017) 
=HEX2OCT("3B4E") 
Converts hexadecimal 3B4E to octal (35516) 
=HEX2OCT("FFFFFFFF00") 
Converts hexadecimal FFFFFFFF00 to octal (7777777400) 

Function details
HEX2OCT
Top of Page
Convert an octal number to binary
To do this task, use the OCT2BIN function.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

A 
B 
Formula 
Description (Result) 
=OCT2BIN(3, 3) 
Converts octal 3 to binary with 3 characters (011) 
=OCT2BIN(7777777000) 
Converts octal 7777777000 to binary (1000000000) 

Function details
OCT2BIN
Top of Page
Convert an octal number to decimal
To do this task, use the OCT2DEC function.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

A 
B 
Formula 
Description (Result) 
=OCT2DEC(54) 
Converts octal 54 to decimal (44) 
=OCT2DEC(7777777533) 
Converts octal 7777777533 to decimal (165) 

Function details
OCT2DEC
Top of Page
Convert an octal number to hexadecimal
To do this task, use the OCT2HEX function.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

A 
B 
Formula 
Description (Result) 
=OCT2HEX(100, 4) 
Converts octal number 100 to hexadecimal with 4 characters (0040) 
=OCT2HEX(7777777533) 
Converts octal number 7777777533 to hexadecimal (FFFFFFFF5B) 

Function details
OCT2HEX
Top of Page