ArcTan Calculator
Find the angle whose tangent equals a given value, with principal value in degrees or radians.
Inputs
Any real number.
arctan(x)
45.00000000
Result (degrees)
45.000000°
Result (radians)
0.78539816
Step by step
Input value
= 1
Compute arctan
arctan(1)
= 45° = 0.78539816 rad
Principal range
= (−90°, 90°)
How it works
The inverse tangent (arctan) returns the angle whose tangent equals x. The principal value is in (−90°, 90°) or (−π/2, π/2). Unlike arcsin/arccos, the domain is all real numbers.
Formula
Inverse tangent
θ = arctan(x), for any real x
- x
- The tangent value
- θ
- The resulting angle in (−90°, 90°)
Frequently Asked Questions
What is arctan(1)?
arctan(1) = 45°, because tan(45°) = 1.
Does arctan have a restricted domain?
No. Unlike arcsin and arccos, arctan accepts any real number — the output is always between −90° and 90° (exclusive).