Trigonometry Calculator

Calculate sin, cos, tan and inverse trig functions instantly in degrees or radians

Common Angles

Trig Identities

Pythagorean Identity

sin^2(x) + cos^2(x) = 1

Tangent Definition

tan(x) = sin(x) / cos(x)

Double Angle (Sin)

sin(2x) = 2sin(x)cos(x)

Double Angle (Cos)

cos(2x) = cos^2(x) - sin^2(x)

Odd Function (Sin)

sin(-x) = -sin(x)

Even Function (Cos)

cos(-x) = cos(x)

Special Angles

Anglesincostan
0010
301/2sqrt(3)/21/sqrt(3)
45sqrt(2)/2sqrt(2)/21
60sqrt(3)/21/2sqrt(3)
9010undef

Conversion

Degrees to Radians

rad = deg x (pi/180)

Radians to Degrees

deg = rad x (180/pi)

Pi

pi = 3.14159...

About This Trigonometry Calculator

This free online trigonometry calculator helps you compute all six trigonometric functions (sine, cosine, tangent, cosecant, secant, and cotangent) as well as their inverse functions (arcsine, arccosine, arctangent). Switch between degrees and radians mode for flexible angle input and output.

Features

  • Standard Trig Functions: Calculate sin, cos, tan, csc, sec, and cot for any angle
  • Inverse Trig Functions: Calculate arcsin, arccos, and arctan to find angles
  • Degrees or Radians: Toggle between degree and radian mode for input and output
  • Real-time Calculation: Results update instantly as you type
  • Copy Results: Easily copy any calculated value to your clipboard
  • Quick Reference: Common angles and trig identities for quick lookup

How Trigonometric Functions Work

Trigonometric functions relate angles to the ratios of sides in a right triangle. The sine of an angle is the ratio of the opposite side to the hypotenuse, the cosine is the ratio of the adjacent side to the hypotenuse, and the tangent is the ratio of the opposite side to the adjacent side. The inverse functions (arcsin, arccos, arctan) do the opposite - given a ratio, they return the corresponding angle.