Trigonometry Calculator
Compute sine, cosine, tangent — and convert between degrees and radians — for any angle. This free online math calculator runs entirely in your browser — no signup, no data sent anywhere.
Inputs
Results
How It Works (Formula & Method)
All three functions are defined on the unit circle. For an angle θ measured counterclockwise from the positive x-axis, cos(θ) is the x-coordinate and sin(θ) is the y-coordinate of the point where the angle meets the unit circle. tan(θ) = sin(θ) / cos(θ). Degree-to-radian conversion uses θ_rad = θ_deg × π / 180.
Worked Example
Below is a worked example using the calculator's default values. The same numbers are pre-filled in the form above so you can press Calculate and see the result without typing anything.
Inputs used:
- Angle: 30
- Unit: deg
With these inputs, the calculator computes the metrics shown in the Results panel. Change any value and press Calculate again to see how the result responds — the live widget and the chart both update instantly.
About the Trigonometry Calculator
The trigonometric functions sin, cos, and tan describe the ratios between sides of a right triangle as a function of one of its angles. They are foundational across geometry, physics, engineering, signal processing, computer graphics, and astronomy.
How to Use This Calculator
Enter any real-valued angle and choose whether it is in degrees (the everyday unit) or radians (the natural mathematical unit, where one full circle is 2π). The calculator outputs sine, cosine, and tangent, plus the conversion of your angle into the opposite unit.
Tips & Considerations
- sin(0) = 0, sin(90°) = 1, sin(180°) = 0, sin(270°) = −1, sin(360°) = 0.
- cos is sin shifted by 90°: cos(θ) = sin(90° − θ).
- tan(90°) is undefined (division by zero); the calculator may show a very large number.
- In programming languages, the standard library Math.sin/cos/tan typically take radians, not degrees.
Frequently Asked Questions
Why use radians instead of degrees?
Radians make calculus formulas clean. The derivative of sin(x) is cos(x) only when x is in radians.
What is tan(90°) exactly?
Mathematically undefined. Computers return very large numbers due to floating-point representation of the limit.
How do I get arcsin/arccos/arctan?
Those (and many more) are available in our Scientific Calculator using sin⁻¹, cos⁻¹, tan⁻¹ notation.
What does the Trigonometry Calculator compute?
The Trigonometry Calculator takes 2 input values and returns 5 results. Compute sine, cosine, and tangent of any angle in degrees or radians. Includes degree-radian conversion.