# Convert numbers to different number systems

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.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. 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)

BIN2DEC

# 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.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. 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)

BIN2HEX

# 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.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. 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)

BIN2OCT

# 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.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. 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)

DEC2BIN

# 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.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. 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)

DEC2HEX

# 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.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. 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)

DEC2OCT

# 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.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. 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)

HEX2BIN

# 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.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. 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)

HEX2DEC

# 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.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. 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)

HEX2OCT

# 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.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. 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)

OCT2BIN

# 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.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. 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)

OCT2DEC

# 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.

1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note   Do not select the row or column headers.

Selecting an example from Help
1. Press CTRL+C.
2. In the worksheet, select cell A1, and press CTRL+V.
3. 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)

OCT2HEX

Applies to:
Excel 2003