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TAN Function (OpenOffice Calc)

Math Beginner OpenOffice Calc Introduction not established

The TAN function in OpenOffice Calc returns the tangent of an angle (in radians). Learn syntax, degree conversion, undefined values, examples, and best practices.

Verification status: Consult the documentation, examples and any stated test scope below. How formula examples are checked

Availability and version history

  • Introduced: Documented by Apache OpenOffice 4.1.16; original introduction not established.
  • Availability: Supported in Apache OpenOffice 4.1.16, verified against its function registry. This identifies a supported release, not a final working version.
  • Scope: Desktop Calc, using the English function name. Availability in other spreadsheet applications is separate.
  • Checked: 2026-10-14 — function reference; versioned support. Documentation/source check; not a new native test. Existing example-specific test claims below retain their stated scope.

The TAN function in OpenOffice Calc returns the tangent of an angle. TAN is essential for trigonometry, geometry, physics, engineering, slopes, and angle‑based modeling.

What the TAN Function Does

  • Computes the tangent of an angle
  • Angle must be in radians
  • Useful for slopes, angles, rotations, and periodic functions
  • Works across sheets
  • Pairs naturally with SIN, COS, and ATAN

TAN is ideal when you need slope ratios or angle‑based transformations.

Syntax

TAN(number)

Arguments:

  • number — Angle in radians
If your angle is in degrees, convert it using:
Degrees * PI() / 180

Important: Undefined Values

TAN is undefined when:

[ \cos(x) = 0 ]

This occurs at:

  • ( \frac{\pi}{2} )
  • ( \frac{3\pi}{2} )
  • ( \frac{5\pi}{2} )
  • …and every odd multiple of ( \frac{\pi}{2} )

Calc returns very large positive or negative numbers near these points.

Basic Examples

Tangent of an angle in radians

=TAN(PI() / 4)

Result: 1

Tangent of 45 degrees

=TAN(45 * PI() / 180)

Result: 1

Tangent using a cell reference

=TAN(A1)

(Assumes A1 is in radians.)

Convert degrees to radians inside TAN

=TAN(RADIANS(A1))

Advanced Examples

Slope from angle

=TAN(AngleRadians)

Angle from slope (inverse)

=ATAN(Slope)

Tangent wave

=TAN(2 * PI() * Frequency * Time)

Avoiding undefined values

=IF(COS(A1)=0; NA(); TAN(A1))

Triangle side ratio

Opposite / Adjacent:

=TAN(AngleRadians)

TAN across sheets

=TAN(Sheet1.A1)

TAN in array formulas

=TAN(A1:A10)

Confirm with Ctrl+Shift+Enter.

Tangent of a sum

=TAN(A1 + A2)

Convert slope to angle in degrees

=ATAN(Slope) * 180 / PI()

Common Errors and Fixes

TAN returns extremely large numbers

Occurs when:

  • Angle is near an undefined point (odd multiples of Ï€/2)
  • COS(angle) ≈ 0

TAN returns unexpected values

Almost always caused by:

  • Using degrees instead of radians
  • Forgetting to convert: Degrees * PI() / 180
  • Incorrect parentheses

TAN returns Err:502 (Invalid argument)

Occurs when:

  • Input is text
  • Input is empty
  • A malformed reference is used

TAN ignores values you expected it to include

TAN ignores:

  • Text numbers ("123")
  • Empty cells
  • Logical values
  • Errors

TAN includes values you expected it to ignore

TAN includes:

  • Dates
  • Times
  • Numeric results of formulas

Err:508 — Missing parenthesis

Usually caused by:

  • Missing )
  • Using commas instead of semicolons

Best Practices

  • Always convert degrees to radians
  • Avoid angles where COS(angle) = 0
  • Use ATAN or ATAN2 to reverse tangent calculations
  • Use named ranges for angles and slopes
  • Keep parentheses clean in multi‑step trig formulas
TAN is perfect for slopes and angles — if you’re converting between rise/run and angle, TAN and ATAN are your best tools.