Trigonometry Calculator

Nine in total: the three basic functions sin, cos, and tan; their inverses asin, acos, and atan; and the three reciprocals csc (1 / sin), sec (1 / cos), and cot (cos / sin). Select a function, enter the angle or ratio, and the result is rounded to six decimal places.

Yes. Forward functions (sin, cos, tan, csc, sec, cot) accept an angle in either degrees or radians - you choose with a toggle. Inverse functions (asin, acos, atan) output the result in both units at the same time, so you can read 0.523599 radians and 30 degrees side by side without doing the conversion yourself.

tan equals sin divided by cos, and cos(90 degrees) is zero, making the ratio undefined. The calculator returns no result at 90, 270, 450, and every odd multiple of 90 degrees. sec shares the same singularity. csc and cot are undefined where sin is zero - at 0, 180, 360, and every multiple of 180 degrees.

Both require an input between -1 and 1, inclusive. Sine and cosine are always in that range, so their inverses have no meaning outside it - enter 1.5 and the calculator returns no result. atan has no such restriction: it accepts any finite number, and its output approaches +90 or -90 degrees (pi/2 or -pi/2 radians) as the input grows large.

All results are rounded to six decimal places using standard double-precision floating-point arithmetic. Six places is enough for textbook problems, surveying, and most engineering estimates while keeping the display clean. The rounding happens at the final output step, not during intermediate calculations.