Why Use This Tool?
Sine, cosine and tangent depend on whether your angle is in degrees or radians — the same number means completely different things. This calculator takes either unit, converts internally, and shows all three ratios plus the degree/radian equivalent.
The inverse panel runs the other direction: given a ratio between −1 and 1, it returns the angle that produces it, in degrees.
How It Works
- Enter an angle and pick degrees or radians.
- Read sin, cos and tan — the unit conversion is shown for reference.
- Use the inverse panel to recover an angle from a known ratio.
Frequently Asked Questions
How do I calculate sine of an angle in degrees?
Enter the angle in degrees and the tool converts to radians internally before applying the function — 45° correctly gives sin = 0.7071.
Why is tan 90° undefined?
Tangent is sine divided by cosine, and cosine of 90° is zero — division by zero. The tool shows 'undefined' instead of an error-sized number.
What are the inverse trig functions for?
They recover the angle from a ratio: asin(0.5) = 30°. Essential when you know two sides of a triangle and need the angle.
Tips & Things to Watch
- Most programming sin/cos bugs are degree-vs-radian mistakes — this tool prevents them.
- Angles outside 0–360° wrap around: sin(450°) = sin(90°).
- Inverse functions return degrees here, matching school trigonometry.