The Excel DEC2BIN Function


The Binary (Base 2) Numeral System uses the digits 0 & 1.

The following table shows the first 8 binary values, along with the equivalent decimal values:


For further information on the binary numeral system, see the Wikipedia Binary Page

Related Function:
Bin2Dec Function

Function Description

The Excel Dec2Bin function converts a decimal number into a Binary (Base 2) number.

The syntax of the function is:

DEC2BIN( number, [places] )

Where the function arguments are as follows:

number-The decimal number that is to be converted to binary.

An optional argument, which specifies the number of characters that you want the returned binary number to have.

If this is greater than the minimum, the binary number will be padded out using leading zeros.

If omitted, the returned binary uses the minimum number of places.

Dec2Bin Function Examples

The following spreadsheets show five examples of the Excel Dec2Bin function.

1=DEC2BIN( 2 )
2=DEC2BIN( 3 )
3=DEC2BIN( 2, 10 )
4=DEC2BIN( -2 )
5=DEC2BIN( 6 )
110  Result is   1*2 + 0
211  Result is   1*2 + 1
30000000010  Result is   1*2 + 0
41111111110  Result is   -2^9 + 2^8 + 2^7 + ... + 2 + 0
5110  Result is   2^2 + 2 + 0

Note that, in the above example spreadsheet, the negative binary number in cell A4 is represented by two's complement notation.

Further details and examples of the Excel Dec2Bin function are provided on the Microsoft Office website.

Dec2Bin Function Errors

If you get an error from the Excel Dec2Bin function this is likely to be one of the following:

Common Errors

Occurs if either:

  • The supplied number argument is < -512 or is > 511;
  • The resulting binary number requires more places than is specified by the supplied [places] argument;
  • The supplied [places] argument is < 0 or > 10.
#VALUE!-Occurs if one or both of the supplied number or the supplied [places] are non-numeric.