About this calculator
Enter any angle, even negative or above 360°.
How to use it
- Enter the angle.
- Choose degrees or radians.
- Read the point and quadrant.
The formula
Point = (cos θ, sin θ)
- reference angle
- acute angle to the x-axis
- quadrant
- I to IV, anticlockwise from the positive x-axis
Worked example
150°
- Quadrant II; reference angle 30°.
- Point = (−√3/2, 1/2) ≈ (−0.866, 0.5).
What the result means
“All Students Take Calculus” recalls which ratios are positive in quadrants I, II, III and IV.
Assumptions
- Real angles.
Limitations
- Results are rounded to 10 significant figures.
Frequently asked questions
What is the unit circle?
A circle of radius 1 centred at the origin.
What is a reference angle?
The acute angle between the terminal side and the x-axis.
Which ratios are positive in quadrant II?
Only sin and cosec.
Last reviewed on 3 October 2026. Found a mistake? Tell us.