BIN2DEC Function

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The Excel BIN2DEC function converts a binary (base-2) number to decimal (base-10) — a staple for digital electronics, low-level programming, and bit manipulation.

Quick answer:
=BIN2DEC("1010") // 1010 (binary) = 10 (decimal)

Syntax

=BIN2DEC(number)
ArgumentDescription
numberRequiredThe binary number to convert, as text or a value.

How to use it

BIN2DEC converts a binary (base-2) value to decimal (base-10). The result is returned as text for non-decimal, or a number for decimal.

=BIN2DEC("1010") // 1010 (binary) = 10 (decimal)

Round-trip tip: every conversion has an inverse — pair this with the reverse function to validate. All base functions cap inputs at 10 characters (signed), so very large numbers need a different approach.

Try it: interactive demo

Live demo

Type a binary value and watch it convert to decimal.

Result:

Practice workbook

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Frequently asked questions

Why is the BIN2DEC result text, not a number?
Base conversions (except to decimal) return text so leading zeros and hex letters are preserved. Wrap in VALUE or the reverse function if you need a number.
What is the places argument for?
It pads the result with leading zeros to a fixed width — e.g. DEC2BIN(5,8) gives 00000101. Handy for byte-aligned output.
Why do I get #NUM!?
The input isn’t a valid binary value (wrong digits), or it exceeds the 10-character signed limit of the base functions.
How do negative numbers work?
The base functions use two’s-complement notation within their 10-digit limit; the top digit signals the sign.

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Related functions: DEC2BIN · BIN2DEC · DEC2HEX · HEX2DEC