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BIN2OCT Function

Excel 2007+

Summary

The Excel BIN2OCT function converts a binary number to its octal (base-8) equivalent. It handles both positive and negative binary numbers using two's complement notation, making it essential for number system conversions in technical calculations.

Syntax

BIN2OCT(number, [places])

Parameters

Parameter	Type	Required	Description
number	`String`	Yes	The binary number (up to 10 bits). Uses two's complement for negative values.
places	`Integer`	No	Desired output length. Pads with leading zeros if specified.

Using the BIN2OCT Function

BIN2OCT is perfect for converting binary data from embedded systems, digital logic, or programming outputs into readable octal format. Use it when working with hardware specifications, bitwise operations, or teaching number systems.

Common BIN2OCT Examples

Basic Binary to Octal Conversion

=BIN2OCT(1001, 3)

Converts binary 1001 (decimal 9) to 3-digit octal: 011.

Without Padding

=BIN2OCT(1100100)

Converts binary 1100100 (decimal 100) to octal 144 without leading zeros.

Maximum Positive Value

=BIN2OCT(1111111111)

Converts 10-bit maximum positive binary to octal 7777777777.

Frequently Asked Questions

BIN2OCT ignores the [places] parameter for negative numbers and always returns a 10-character octal result using two's complement.

Exactly 10 characters (10 bits). Longer inputs return #NUM! error.

Common Errors and Solutions

#NUM!

Cause: Invalid binary number, more than 10 bits, or result exceeds specified places

Solution: Verify binary format (only 0s and 1s), length ≤10, and sufficient places value

#VALUE!

Cause: Places argument is non-numeric

Solution: Ensure places contains a valid number

#NUM! (negative places)

Cause: Places argument is negative

Solution: Use only positive integers or omit places

Notes

Sign bit is always the leftmost (most significant) bit
Negative numbers use two's complement notation
Places < 0 returns #NUM! error
Non-integer places values are truncated
Perfect for microcontroller programming and digital electronics

Compatibility

Available in: Excel 2007, Excel 2010, Excel 2013, Excel 2016, Excel 2019, Excel 2021, Microsoft 365

Not available in: Excel 2003 and earlier

Content last reviewed: December 9, 2025
Update frequency: As needed
Excel versions tested: Excel 2007+