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IMTAN Function

Excel 2007+

Summary

The Excel IMTAN function calculates the tangent of a complex number provided in x+yi or x+yj format. This engineering function handles trigonometric calculations for complex values that standard TAN cannot process.

Syntax

IMTAN(inumber)

Parameters

Parameter	Type	Required	Description
inumber	`Complex`	Yes	The complex number (in x+yi or x+yj text format) for which to calculate the tangent

Using the IMTAN Function

IMTAN enables tangent calculations for complex numbers, crucial in electrical engineering, signal processing, and advanced mathematical modeling where imaginary components are involved. Pair it with COMPLEX function to create inputs from real/imaginary parts.

Common IMTAN Examples

Basic Complex Tangent

=IMTAN("4+3i")

Calculates tangent of complex number 4+3i, returning approximately 0.0049+1.0007i

Using COMPLEX Helper

=IMTAN(COMPLEX(4,3))

Combines COMPLEX with IMTAN for cleaner formulas using separate real/imaginary inputs

Frequently Asked Questions

Must be in 'x+yi' or 'x+yj' text format, or created via COMPLEX function.

#NUM! for invalid complex format, #VALUE! for logical values.

Common Errors and Solutions

#NUM! error

Cause: inumber not in valid x+yi or x+yj format

Solution: Use COMPLEX(real_num, i_num) or verify format

#VALUE! error

Cause: inumber contains logical values

Solution: Ensure input is numeric or proper complex format

Notes

IMTAN is part of Excel's 60+ Engineering functions for complex numbers
Use COMPLEX() to build inputs from separate real/imaginary components
Result always returns in x+yi complex format
Available since Excel 2007

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+