Our mission
Inverse Tangent Calculator exists to make one small but important piece of maths fast and clear: turning a ratio, two sides or a point into an angle. Students, teachers, engineers, surveyors, game developers and DIY builders use the inverse tangent every day, and we think they deserve a tool that is accurate, explains itself and stays out of the way.
What makes it different
- Every input you need. A single value, a fraction or expression, opposite and adjacent sides, or an (x, y) point with full atan2 quadrant handling.
- Every unit you need. Degrees, radians, gradians, turns, arcminutes, arcseconds, milliradians, microradians, π radians and degrees-minutes-seconds.
- It shows its working. Exact values such as π/6 are recognised, and each answer comes with a step-by-step solution, a triangle, a unit circle and an interactive graph.
- Private by design. All calculations run in your browser. Nothing you type is sent to a server.
- Fast and accessible. The site is built to load quickly on any phone and to work with a keyboard and screen readers.
How we check accuracy
Results use your browser's IEEE-754 double precision maths (about 15–17 significant digits). Special angles are matched against exact values, and the reference tables on the home page are generated from the same code that powers the calculator, so they always agree. If you ever spot a result that looks wrong, please tell us and we will investigate it quickly.
Who we are
Inverse Tangent Calculator is an independent project run by a small team of developers and maths educators. We are not affiliated with any school, publisher or company, and the calculator will always be free to use.
Get in touch
Questions, ideas or corrections are always welcome. Use the contact form or email contact@inversetangentcalculator.org.