Trigonometry Calculator

One Tool for Every Basic Ratio

One trigonometry calculator covers sine, cosine, and tangent in a single place. You pick the function, enter a number, and the tool evaluates it directly. Students verifying identities, engineers resolving forces, and programmers testing math libraries all save time because no scratch work is needed to recall which ratio belongs to which function.

Because one form handles all three ratios, it doubles as a quick reference. Keep it open alongside your homework and you will spot angle patterns faster.

Core Formulas and a Worked Example

The three ratios are sin(x) = opposite / hypotenuse, cos(x) = adjacent / hypotenuse, and tan(x) = sin(x) / cos(x). They are tied together by the identity sin^2(x) + cos^2(x) = 1, a handy check on any result the calculator produces. The Metric selector tells the tool which unit your x uses before anything is computed.

Take x = 45 degrees as a worked example. Both sin 45 and cos 45 equal about 0.707, so tan 45 = 0.707 / 0.707 = exactly 1. The identity holds as well, since 0.707^2 + 0.707^2 comes to roughly 1.000.

How to Use It

Choose the function from the Function dropdown, type the value into the Number (x=) box, then select degrees or radians under Metric and press Calculate. To confirm tan 45 in degrees, enter 45 and expect exactly 1. Cosine of 60 in degrees should return 0.5.

Domains and units are the two classic pitfalls. Tan is undefined at 90 degrees and at every 180 degree step beyond, because cos turns to 0 there. The unit choice also changes everything: sin 30 in degrees gives 0.5, while sin 30 in radians gives -0.988, so always confirm which unit your source intends.