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.
Note
This article describes the different number systems. To change the character used to separate thousands or decimals based on your region, see the Change the character used to separate thousands or decimals topic on Microsoft Q&A.
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 |
Convert a binary number to decimal
To do this task, use the BIN2DEC function.
| Formula | Description (Result) |
|---|---|
| =BIN2DEC(1100100) | Converts binary 1100100 to decimal (100) |
| =BIN2DEC(1111111111) | Converts binary 1111111111 to decimal (-1) |
Convert a binary number to hexadecimal
To do this task, use the BIN2HEX function.
| 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) |
Convert a binary number to octal
To do this task, use the BIN2OCT function.
| 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) |
Converts a decimal number to binary
To do this task, use the DEC2BIN function.
| Formula | Description (Result) |
|---|---|
| =DEC2BIN(9, 4) | Converts decimal 9 to binary with 4 characters (1001) |
| =DEC2BIN(-100) | Converts decimal -100 to binary (1110011100) |
Convert a decimal number to hexadecimal
To do this task, use the DEC2HEX function.
| Formula | Description (Result) |
|---|---|
| =DEC2HEX(100, 4) | Converts decimal 100 to hexadecimal with 4 characters (0064) |
| =DEC2HEX(-54) | Converts decimal -54 to hexadecimal (FFFFFFFFCA) |
Convert a decimal number to octal
To do this task, use the DEC2OCT function.
| Formula | Description (Result) |
|---|---|
| =DEC2OCT(58, 3) | Converts decimal 58 to octal (072) |
| =DEC2OCT(-100) | Converts decimal to octal (7777777634) |
Convert a hexadecimal number to binary
To do this task, use the HEX2BIN function.
| 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) |
Convert a hexadecimal number to decimal
To do this task, use the HEX2DEC function.
| 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) |
Convert a hexadecimal number to octal
To do this task, use the HEX2OCT function.
| 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) |
Convert an octal number to binary
To do this task, use the OCT2BIN function.
| Formula | Description (Result) |
|---|---|
| =OCT2BIN(3, 3) | Converts octal 3 to binary with 3 characters (011) |
| =OCT2BIN(7777777000) | Converts octal 7777777000 to binary (1000000000) |
Convert an octal number to decimal
To do this task, use the OCT2DEC function.
| Formula | Description (Result) |
|---|---|
| =OCT2DEC(54) | Converts octal 54 to decimal (44) |
| =OCT2DEC(7777777533) | Converts octal 7777777533 to decimal (-165) |
Convert an octal number to hexadecimal
To do this task, use the OCT2HEX function.
| 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) |