The Excel BIN2DEC function converts a binary number to the decimal equivalent. The input number must contain only zeros and ones and be less than 10 characters long, otherwise the function returns the #NUM! error value.


Converts a binary number to decimal

Return value 

Decimal Number


  • number - The binary number you want to convert to decimal.



Usage notes 

The first bit of the binary number indicates whether the number is positive or negative. The other nine digits represent the size of the number, the max of which is 511 (2^9 - 1). A negative binary number is expected to use the two's complement notation.

BIN2DEC Input Range
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Dave Bruns

Hi - I'm Dave Bruns, and I run Exceljet with my wife, Lisa. Our goal is to help you work faster in Excel. We create short videos, and clear examples of formulas, functions, pivot tables, conditional formatting, and charts.