IMLOG2 Function in Excel: Base-2 Log of a Complex Number

IMLOG2 Function in Excel: Base-2 Log of a Complex Number 1
⏱ 1 min readUpdated 5 October 2026

Complex numbersLevel: ExpertAvailable in: Excel 2007+

In this article
  1. Syntax
  2. Examples
  3. Example 1
  4. IMLOG2 in practice
  5. Where you will use it
  6. Worked example
  7. Mistakes people make
  8. Related functions

IMLOG2 returns log2(z). Complex numbers are text like 3+4i; build them with COMPLEX.

Advertisement

Syntax

=IMLOG2(inumber)
Argument What it means
inumber Complex number as text, e.g. “3+4i”

Examples

Example 1

=IMLOG2(A2)

Result: 2.32192809488736+1.33780421245098i. See the worked example table below for more cases.

IMLOG2 in practice

Where you will use it

  • AC circuit calculations (impedance, phase)
  • Signal processing
  • Engineering coursework

Worked example

zFormulaResult
3+4i=IMLOG2(A2)2.32192809488736+1.33780421245098i
1-i=IMLOG2(A3)0.5-1.1330900354568i
2i=IMLOG2(A4)1+2.2661800709136i

Results calculated in Excel.

Mistakes people make

MistakeWhat to do instead
Spaces inside the text"3 + 4i" gives #NUM!; write 3+4i
Result is textUse IMREAL/IMAGINARY to get numbers back

COMPLEX · IMABS · IMREAL

📚 Part of the free Excel course: Beginner → Expert · Try it in the Formula Lab or ask the AI Helper.

Keep reading

Excel Functions A–ZOCT2DEC Function in Excel: Octal to DecimalExcel Functions A–ZBINOM.DIST.RANGE Function in Excel: Probability of Successes in a RangeExcel Functions A–ZTIME Function in Excel: Build a Time From Hours, Minutes, Seconds
Advertisement
✨ Ask AI about this article

Stuck on a step? Ask a question and the AI answers using this article.

Free · AI can be wrong