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IMLOG2 Function

Excel 2007+

Summary

The Excel IMLOG2 function calculates the base-2 logarithm of a complex number entered in standard x+yi format. This engineering function is essential for complex number calculations in fields like electrical engineering and signal processing.

Syntax

IMLOG2(inumber)

Parameters

Parameter	Type	Required	Description
inumber	`Complex`	Yes	A complex number entered as text in x+yi or x+yj format

Using the IMLOG2 Function

IMLOG2 is used in advanced engineering calculations involving complex numbers where base-2 logarithms are required. It's particularly useful in digital signal processing, control systems, and electrical engineering applications that work with complex exponential functions.

Common IMLOG2 Examples

Basic IMLOG2 Calculation

=IMLOG2("3+4i")

Returns the base-2 logarithm of 3+4i, which equals approximately 2.321928+1.337804i

Using COMPLEX with IMLOG2

=IMLOG2(COMPLEX(3,4))

Calculates base-2 log of complex number created from real (3) and imaginary (4) parts

Frequently Asked Questions

Use x+yi format where x is the real part and y is the imaginary part (e.g., "3+4i" or "-2-3j").

IMLOG2 specifically returns base-2 logarithm of complex numbers, while LOG works with real numbers and any base.

Yes, decimals are supported: "1.5+2.7i" works perfectly.

Common Errors and Solutions

#NUM!

Cause: Invalid complex number format

Solution: Ensure proper x+yi format with correct + or - signs

#VALUE!

Cause: Non-text complex number input

Solution: Enter complex number as text string in quotes

#NAME?

Cause: IMLOG2 not recognized

Solution: Confirm Excel version (2007+) and correct spelling

Notes

Base-2 logarithm calculated from natural logarithm: log₂(z) = ln(z)/ln(2)
Use COMPLEX function to create complex numbers from separate real/imaginary parts
IMLOG2 returns results in standard complex format
Related functions: IMLOG10 (base-10), IMLN (natural log)

Compatibility

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

Not available in: Excel 2003, Excel XP, Excel 2000, Excel 97

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