Cos Calculator
Calculate the cosine of any angle in degrees or radians with step-by-step working.
About Cos Calculator
The cosine function returns the ratio of the adjacent side to the hypotenuse in a right triangle. For any angle θ, cos(θ) ranges from −1 to 1. cos(0°)=1, cos(90°)=0, cos(180°)=−1.
Formula
Cosine definition
cos θ = adjacent / hypotenuse
- θ
- The angle
- adjacent
- Side adjacent to θ
- hypotenuse
- Longest side
Worked example
With the default values below, Cos Calculator returns cos(θ) of 0.5000000000. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Angle (θ)
- 60
- Angle unitone of Degrees, Radians
- Degrees
Results
- cos(θ)
- 0.5000000000
- Angle (degrees)
- 60.000000 °
- Angle (radians)
- 1.04719755
Step by step
- 1Convert to radians
- 2Apply cos function= 0.5
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 10 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
What is cos(60°)?
cos(60°) = 0.5. Standard values: cos(0°)=1, cos(30°)≈0.8660, cos(45°)≈0.7071, cos(60°)=0.5, cos(90°)=0.
How are sin and cos related?
They are complementary: sin(θ) = cos(90° − θ). Also, sin²θ + cos²θ = 1 for all θ (the Pythagorean identity).