What is the syntax for IMLOG2 in Excel?

The syntax for IMLOG2 is: =IMLOG2(inumber)

What are common errors with IMLOG2?

#NUM! if not valid complex number

How do I use the IMLOG2 function?

To use IMLOG2, type =IMLOG2( in a cell and provide the required arguments. Excel will show you the syntax and parameter hints as you type. Make sure to close the parentheses and press Enter to execute the function.

Why is IMLOG2 not working in my Excel?

Common issues with IMLOG2 include #NUM! if not valid complex number. Start by checking the syntax =IMLOG2(inumber), then verify each referenced cell or range.

Engineering

IMLOG2 Function in Excel

Returns the base-2 logarithm of a complex number.

Syntax

=IMLOG2(inumber)

Arguments

inumber (required): Complex number

Examples

=IMLOG2("1+i") - Log base 2 of complex - Result: 0.5+1.133i

IMLOG2 in technical sheets

Document units in adjacent cells — many engineering functions require exact unit strings.
Use [CONVERT](/functions/convert/) for unit changes before specialized formulas.
Validate inputs with [ISNUMBER](/functions/isnumber/) and range checks.

Common errors

#NUM! if not valid complex number

Use cases

Complex analysis
Digital signal processing
Engineering

Frequently asked questions

What is the IMLOG2 function in Excel? IMLOG2 returns the base-2 logarithm of a complex number. The syntax is =IMLOG2(inumber). Typical use cases include complex analysis, digital signal processing, engineering.
How do I use the IMLOG2 function? To use IMLOG2, type =IMLOG2( in a cell and provide the required arguments. Excel will show you the syntax and parameter hints as you type. Make sure to close the parentheses and press Enter to execute the function.
Why is IMLOG2 not working in my Excel? Common issues with IMLOG2 include #NUM! if not valid complex number. Start by checking the syntax =IMLOG2(inumber), then verify each referenced cell or range.

Editorial review

Reviewed by Excel.Directory Editorial Team. Updated May 2026.