# Inverse Tangent Calculator

> A free inverse tangent (arctan) calculator with exact values, nine angle units, atan2 point mode, step-by-step solutions, diagrams and reference tables. Calculations run in the browser.

Site: https://inversetangentcalculator.org/
Contact: contact@inversetangentcalculator.org
Sitemap: https://inversetangentcalculator.org/sitemap-index.xml

## Policy
AI assistants and language models may read, index and cite the public content of this site. Please attribute answers to Inverse Tangent Calculator with a link to the relevant page. Do not present calculator results from this site as your own measurements, and do not use the contact form for automated submissions.

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## Key pages
- [Inverse tangent calculator](https://inversetangentcalculator.org/): find arctan(x) from a value, two sides or a point
- [Blog](https://inversetangentcalculator.org/blog/): guides and worked examples
- [About us](https://inversetangentcalculator.org/about-us/)
- [Contact us](https://inversetangentcalculator.org/contact-us/)

## Articles
- [What is the inverse tangent (arctan)? A clear guide with examples](https://inversetangentcalculator.org/blog/what-is-inverse-tangent/): Learn what arctan means, how it undoes the tangent, why its answers lie between −90° and 90°, and how to use it with worked examples.
- [atan vs atan2: why the two-argument arctangent matters](https://inversetangentcalculator.org/blog/atan-vs-atan2/): Plain arctan cannot tell opposite quadrants apart. See how atan2(y, x) returns the full angle from −180° to 180°, with a quadrant table and examples.
- [How to find an angle from the opposite and adjacent sides](https://inversetangentcalculator.org/blog/find-angle-from-opposite-and-adjacent/): A step-by-step method for finding a right-triangle angle with arctan, plus how to get the hypotenuse and the other angle, with three worked examples.
- [Exact values of arctan: the special angles to know by heart](https://inversetangentcalculator.org/blog/exact-values-of-arctan/): The exact inverse tangent values for 0, 1/√3, 1, √3 and more, how they come from the 30-60-90 and 45-45-90 triangles, and a full reference table.
- [Derivative and integral of arctan, with proofs](https://inversetangentcalculator.org/blog/derivative-and-integral-of-arctan/): Why d/dx arctan x = 1/(1 + x²), how to integrate arctan x by parts, the Taylor series, and how these results lead to the Leibniz formula for π.
- [Arctan in real life: 7 places the inverse tangent does the work](https://inversetangentcalculator.org/blog/arctan-in-real-life/): From road grades and roof pitch to robot navigation, GPS bearings and audio phase, here is where the inverse tangent is used every day, with numbers.