TAN Function (OpenOffice Calc)
The TAN function in OpenOffice Calc returns the tangent of an angle (in radians). Learn syntax, degree conversion, undefined values, examples, and best practices.
Compatibility
▾| Excel | ✔ |
| Gnumeric | ✔ |
| Google_sheets | ✔ |
| Libreoffice | ✔ |
| Numbers | ✔ |
| Onlyoffice | ✔ |
| Openoffice | ✔ |
| Wps | ✔ |
| Zoho | ✔ |
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 π/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.