Trig Calculator

Where machinists actually use this

Sine bars, tapers, dovetails, and angled features all come down to the same handful of trig relationships — this exists so you can get sin, cos, and tan (or go backward from a measured ratio to an angle) without hunting for a scientific calculator or trying to remember which button does what on your phone's app.

Why sin, cos, and tan cover almost everything

Every other common trig value — cosecant, secant, cotangent — is just the reciprocal of one of these three, so this calculator gives you all six from a single angle input. For inverse lookups (ratio back to angle), sin, cos, and tan are also the three you'll actually need for shop work; their reciprocal inverses are rarely useful on their own.

Watch the domain on inverse lookups

Inverse sine and inverse cosine only accept ratios between −1 and 1 — a value outside that range isn't a valid sine or cosine of any real angle, and usually means a units mix-up or an arithmetic error upstream, not a calculator problem.