TAN Function in Excel: Tangent of an Angle

TAN Function in Excel: Tangent of an Angle featured illustration

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⏱ 2 min readUpdated 5 October 2026

MathLevel: IntermediateAvailable in: Excel 2007+

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

TAN links an angle to a slope. Radians again — wrap degrees in RADIANS().

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Syntax

=TAN(number)
Argument What it means
number Radians.

Examples

Example 1

=B2*TAN(RADIANS(C2))

Height of a building from distance and viewing angle.

TAN in practice

Where you will use it

  • Height from distance and angle
  • Slopes and gradients
  • Trigonometry

Worked example

DegreesFormulaResult
45=ROUND(TAN(RADIANS(A2)),4)1
30=ROUND(TAN(RADIANS(A3)),4)0.5774
60=ROUND(TAN(RADIANS(A4)),4)1.7321

Results calculated in Excel.

Mistakes people make

MistakeWhat to do instead
DegreesConvert with RADIANS
90 degreesGives a huge number, not an error

ATAN · SIN · RADIANS

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📎 Practice files for this article

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    Practice workbook: Math & rounding24 tasks on realistic sales data — type your formula, the Check column turns green when it is right. Answers sheet included.
    ⬇ XLSX · 35 KB

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