Below is an inverse tangent calculator (or arctan calculator), which calculates an angle from the ratio from the tangent function. Enter a result and choose to return radians or degrees, then compute the angle.
Inverse Tangent Calculator
Using the Arctangent Calculator
To use the tool to find the angle from a tangent, enter the ratio and the units you'd like and compute.
- Tangent - ratio of the opposite side to the adjacent side
- Output Degrees or Radians? - choose to return degrees or radians
Once you're happy, click the "Compute Arctan" button.
- Angle - the angle you'd input if you wanted to get the tangent you entered
What is the arctangent or inverse tangent?
Arctangent is the inverse of the tangent, which is the ratio of the opposite side to the adjacent side in a right triangle.
Arctangent as a formula
Inverse tangent is usually abbreviated as "arctan" or "atan", as in the following equation:
Where it is the inverse of tangent, or: