How to use the BIN2DEC() function in Excel

This function converts a binary number into a decimal number.

Syntax
BIN2DEC(number)

Argument

• number(required) – The binary number to be converted, which must:
  • Be in two’s complement notation
  • Contain no more than 10 digits

Background
For detailed information about number systems and two’s complement notation, refer to the « Number Systems » section in the introduction to these functions.

Examples
The following examples demonstrate the BIN2DEC() function:

• =BIN2DEC(1110)returns 14
• =BIN2DEC(111111111)returns 511
• =BIN2DEC(1111111111)returns -1 (demonstrating two’s complement representation)
• =BIN2DEC(1111111110)returns -2

Key Notes

1. The function handles both positive and negative numbers through two’s complement representation
2. The 10-digit limit is important as it determines the range of numbers that can be represented
3. For positive numbers, the conversion is straightforward binary-to-decimal
4. For negative numbers (indicated by a leading 1 in two’s complement), the function properly interprets the two’s complement notation