Calculate the secant of an angle, or find the angle from a known secant value.
How to Use the Secant Calculator
In Angle → sec mode, enter an angle to find its secant. In sec → Angle mode, enter a secant value instead to find the angle.
sec(θ) = 1 ÷ cos(θ)Secant is cosine's reciprocal, so it's undefined wherever cosine hits zero (90°, 270°) and, like cosecant, can never take a value strictly between −1 and 1 — the reciprocal of a fraction smaller than 1 in magnitude is always a number 1 or larger in magnitude. This calculator rejects secant values in that forbidden gap rather than returning an angle that doesn't exist.