ATAN Function in Excel: Angle From a Slope

ATAN Function in Excel: Angle From a Slope featured illustration

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⏱ 2 min readUpdated 5 October 2026

MathLevel: ExpertAvailable in: Excel 2007+

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

ATAN turns a slope (rise/run) into an angle. ATAN2 handles all four quadrants.

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Syntax

=ATAN(number)
Argument What it means
number Slope.

Examples

Example 1

=DEGREES(ATAN(1/12))

A 1:12 wheelchair ramp is about 4.8 degrees.

ATAN in practice

Where you will use it

  • Angle of a slope (rise/run)
  • Ramp and roof angles
  • Direction from a gradient

Worked example

A 1:12 wheelchair ramp is about 4.76°.

Rise/RunFormulaResult
1=ROUND(DEGREES(ATAN(A2)),2)45
0.0833=ROUND(DEGREES(ATAN(A3)),2)4.76
10=ROUND(DEGREES(ATAN(A4)),2)84.29

Results calculated in Excel.

Mistakes people make

MistakeWhat to do instead
Quadrant lostATAN can't tell directions apart; use ATAN2(x,y)
RadiansUse DEGREES

ATAN2 · TAN

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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

Free to use for learning. Files with macros (.bas) are plain text — import them with Alt+F11 → File → Import File, and always test on a copy.

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