Trigonometry Calculator - Sin, Cos, Tan, Exact Values & Inverse Functions
Trigonometry Calculator
All six trig functions, exact values at special angles, and inverses
Six Functions at Once
Sine, cosine and tangent, plus their reciprocals cosecant, secant and cotangent, in one calculation.
Exact Values
At multiples of 30° and 45° you also get the exact form, such as sin 60° = √3/2, alongside the decimal.
Any Unit, Both Ways
Use degrees, radians or gradians, and go backwards from a value to an angle with asin, acos and atan.
Full Privacy
Everything is calculated in your browser.
Trigonometry in Brief
In a right triangle, sine is opposite over hypotenuse, cosine is adjacent over hypotenuse and tangent is opposite over adjacent. On the unit circle, cos θ and sin θ are the x and y coordinates of the point at angle θ, which is how the functions extend to any angle, including negative ones and those beyond 360°.
Some values are undefined: tan 90° and sec 90° would divide by zero, as would csc and cot at 0° and 180°. Results within a trillionth of a clean number are snapped to it, so sin 180° reads 0 instead of the 1.2 × 10⁻¹⁶ that raw floating-point arithmetic produces. Inverse functions return the principal value: asin and atan give −90° to 90°, acos gives 0° to 180°.
Key Takeaways
- Clean output: No stray 1e-16 values: exact zeros show as 0.
- Quadrant shown: See which quadrant the angle falls in and its value between 0° and 360°.
- Domain-checked: asin and acos reject values outside −1 to 1 with a clear message.