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Trigonometry Calculators

Cosine Calculator

Calculate cos(θ) for any angle in degrees or radians, with exact values for special angles and the related reciprocal function.

Enter values

Results update as you type.

Result

cos(θ)

0.8660254038

sec(θ)
1.1547005384
Angle in radians
0.52359878
Angle in degrees
30

About the Cosine Calculator

Calculate cos(θ) for any angle in degrees or radians, with exact values for special angles and the related reciprocal function.

Also known as: cos calculator, cos of angle, cosine function, cos x.

How to use this calculator

  1. Enter angle θ, unit.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

cos θ = adjacent / hypotenuse

Worked example

Using the values pre-filled in the calculator above:

  • Angle θ = 30
  • Unit: Degrees

the calculator returns:

  • cos(θ): 0.8660254038
  • sec(θ): 1.1547005384
  • Angle in radians: 0.52359878
  • Angle in degrees: 30