Math & Statistics · Browser · Free

Trigonometry Calculator

Choose a function or an inverse function, type a value, and press Calculate. The same form has Right triangle mode, where you enter the sides and angles you know.

Two modes in one form

The Mode selector switches the form between two jobs. In Trigonometric functions mode you pick sin, cos, tan, csc, sec or cot, or the matching inverse — arcsin, arccos, arctan, arccsc, arcsec or arccot — type a number into Value (x), set the Angle unit to ° or rad, and press Calculate.

Right triangle mode asks for the parts of a triangle instead: Side a, Side b, Side c, Angle A and Angle B. Enter the ones you know and press the same Calculate button.

Reading what comes back

Nothing is worked out until you press the button. Answers appear in cards below it, and each card carries a Copy action that writes that result and its unit to your clipboard. Clear resets the form so you can try another value.

Trigonometric functions mode runs in either direction: an angle goes in and a ratio comes back, as in sin(30°) = 0.5 and tan(45°) = 1. An inverse function takes the ratio and gives an angle back.

The right triangle formula

For an angle A in a right triangle the functions are ratios of two sides: sin A = opposite / hypotenuse, cos A = adjacent / hypotenuse and tan A = opposite / adjacent. The other three flip those ratios over: csc A = hypotenuse / opposite, sec A = hypotenuse / adjacent and cot A = adjacent / opposite.

The rows below show that pairing at work: sin(30°) = 0.5 sits beside csc(30°) = 2, cos(60°) = 0.5 sits beside sec(60°) = 2, and tan(45°) = 1 sits beside cot(45°) = 1.