OCT2BIN function

This article describes the formula syntax and usage of the OCT2BIN  function in Microsoft Excel.


Converts an octal number to binary.


OCT2BIN(number, [places])

The OCT2BIN function syntax has the following arguments:

  • Number    Required. The octal number you want to convert. Number may not contain more than 10 characters. The most significant bit of number is the sign bit. The remaining 29 bits are magnitude bits. Negative numbers are represented using two's-complement notation.

  • Places    Optional. The number of characters to use. If places is omitted, OCT2BIN uses the minimum number of characters necessary. Places is useful for padding the return value with leading 0s (zeros).


  • If number is negative, OCT2BIN ignores places and returns a 10-character binary number.

  • If number is negative, it cannot be less than 7777777000, and if number is positive, it cannot be greater than 777.

  • If number is not a valid octal number, OCT2BIN returns the #NUM! error value.

  • If OCT2BIN requires more than places characters, it returns the #NUM! error value.

  • If places is not an integer, it is truncated.

  • If places is nonnumeric, OCT2BIN returns the #VALUE! error value.

  • If places is negative, OCT2BIN returns the #NUM! error value.


Copy the example data in the following table, and paste it in cell A1 of a new Excel worksheet. For formulas to show results, select them, press F2, and then press Enter. If you need to, you can adjust the column widths to see all the data.




=OCT2BIN(3, 3)

Converts octal 3 to binary with 3 characters



Converts octal 7777777000 to binary


Applies To: Excel 2016, Excel 2010, Excel Starter, Excel 2013, Excel Online, Excel 2016 for Mac, Excel for Mac 2011, Excel 2007

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