ATAN Function (OpenOffice Calc)
The ATAN function in OpenOffice Calc returns the arctangent (inverse tangent) of a value, in radians. Learn syntax, domain behavior, examples, and best practices.
Compatibility
▾| Excel | ✔ |
| Gnumeric | ✔ |
| Google_sheets | ✔ |
| Libreoffice | ✔ |
| Numbers | ✔ |
| Onlyoffice | ✔ |
| Openoffice | ✔ |
| Wps | ✔ |
| Zoho | ✔ |
What the ATAN Function Does ▾
- Returns the angle whose tangent equals the input
- Output is in radians
- Input can be any real number
- Useful for slopes, rotations, and inverse trig calculations
- Works across sheets
ATAN is ideal when you need to convert slope ratios into angles.
Syntax ▾
ATAN(number)
Arguments:
- number — Any real number (positive, negative, or zero)
ATAN returns an angle in radians.
Convert to degrees using:
Convert to degrees using:
ATAN(x) * 180 / PI()
Range of Output ▾
ATAN returns angles in the range:
[ -\frac{\pi}{2} \le \text{atan}(x) \le \frac{\pi}{2} ]
This means ATAN cannot determine the quadrant — for that, use ATAN2.
Basic Examples ▾
Arctangent of 1
=ATAN(1)
Result (radians): 0.785398163
Equivalent to 45°.
Convert to degrees
=ATAN(1) * 180 / PI()
ATAN using a cell reference
=ATAN(A1)
Convert slope to angle
=ATAN(Slope)
Advanced Examples ▾
Angle of a line from rise/run
=ATAN(Rise / Run)
Convert slope to degrees
=DEGREES(ATAN(Slope))
ATAN across sheets
=ATAN(Sheet1.A1)
ATAN in array formulas
=ATAN(A1:A10)
Confirm with Ctrl+Shift+Enter.
Compute angle of a vector (2D)
=ATAN(Y / X)
(But ATAN2 is preferred.)
Convert angle back to slope
=TAN(ATAN(A1))
Always returns A1.
Use ATAN for smooth easing curves
=ATAN(t)
Use ATAN for asymptotic growth modeling
=A * ATAN(B * x) + C
ATAN vs ATAN2 ▾
| Function | Input | Handles Quadrants? | Typical Use |
|---|---|---|---|
| ATAN(x) | One ratio (y/x) | ❌ No | Slope → angle |
| ATAN2(y; x) | Two coordinates | ✔ Yes | Vector angle |
If you need the true direction of a vector, use ATAN2.
Common Errors and Fixes ▾
ATAN returns Err:502 (Invalid argument)
Occurs when:
- Input is text
- Input is empty
- A malformed reference is used
ATAN returns unexpected results
Possible causes:
- Forgetting that output is in radians
- Using degrees without converting
- Using ATAN instead of ATAN2 for vectors
ATAN ignores values you expected it to include
ATAN ignores:
- Text numbers (
"123") - Empty cells
- Logical values
- Errors
ATAN includes values you expected it to ignore
ATAN includes:
- Dates
- Times
- Numeric results of formulas
Err:508 — Missing parenthesis
Usually caused by:
- Missing
) - Using commas instead of semicolons
Best Practices ▾
- Use ATAN for slope‑to‑angle conversions
- Use ATAN2 for vector angles or quadrant‑aware calculations
- Convert radians to degrees when needed
- Use named ranges for slope and coordinate values
- Pair ATAN with TAN for reversible transformations
ATAN is perfect for slopes — ATAN2 is perfect for directions. Use each where it shines.