Calculate the tangent of an angle, or find the angle from a known tangent value.

How to Use the Tangent Calculator

Same toggle pattern as Sine and Cosine — pick a direction, then enter the one known value.

tan(θ) = opposite ÷ adjacent = sin(θ) ÷ cos(θ)

Tangent breaks where cosine hits zero — at 90° and 270°, dividing by zero has no answer, so the function is simply undefined there. Graph it and you'll see the curve rocket toward infinity as it approaches those angles from either side, then reappear from the opposite infinity just past them.

Unlike sine and cosine, tangent isn't boxed into −1 to 1 — the ratio of opposite to adjacent can grow without limit as an angle nears 90°, so it can output any real number. That's also why arctan, unlike arcsin and arccos, accepts any real number as input rather than being restricted to a narrow range. This Tangent Calculator computes both directions.