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IMABS Function

Excel 2007+

Summary

The Excel IMABS function calculates the absolute value (modulus) of a complex number expressed in standard x + yi or x + yj format. This engineering function extracts the magnitude from complex numbers used in electrical engineering, physics, and mathematical computations.

Syntax

IMABS(inumber)

Parameters

Parameter	Type	Required	Description
inumber	`Complex`	Yes	The complex number for which to calculate the absolute value. Must be in "x+yi" or "x+yj" format.

Using the IMABS Function

IMABS is crucial for complex number analysis in Excel, particularly in electrical engineering applications. It computes the modulus (distance from origin in complex plane) using the formula √(x² + y²) where the complex number is x + yi.

Common IMABS Examples

Basic IMABS Example

=IMABS("5+12i")

Calculates the absolute value of 5+12i, which returns 13 (√(5²+12²) = √(25+144) = √169 = 13)

Real-World Engineering Example

=IMABS("3-4i")

Absolute value of 3-4i returns 5, commonly used in impedance calculations

With COMPLEX Function

=IMABS(COMPLEX(7,24))

Converts real/imaginary parts to complex number first, then gets absolute value (25)

Frequently Asked Questions

IMABS accepts complex numbers in "x+yi" or "x+yj" text format, like "5+12i" or "3-4i".

Use the COMPLEX(real_num, i_num) function to convert separate real and imaginary parts into proper complex number format.

IMABS returns a real number representing the modulus (absolute value) of the complex number.

Common Errors and Solutions

#VALUE! error

Cause: inumber is not a valid complex number format

Solution: Ensure complex number is in correct "x+yi" format or use COMPLEX() function

#NUM! error

Cause: Invalid complex number syntax

Solution: Check that the format follows x + yj pattern with proper operators

Notes

Formula: |z| = √(x² + y²) where z = x + yi
Any text string that can't be interpreted as a complex number returns #VALUE!
IMABS ignores the angle/direction, returns only magnitude
i and j are both valid imaginary unit notations

Compatibility

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

Not available in: Excel 2003 and earlier versions

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