Sine Calculator
Calculate the sine of any angle in degrees or radians, with the radian conversion and the matching cosine and tangent shown.
How to use it
- Enter the angle and choose degrees or radians.
- Sine always returns a value between −1 and 1.
- The other two ratios are shown for the same angle.
Examples
| sin(0°) | 0 |
| sin(30°) | 0.5 |
| sin(90°) | 1 |
Sine is the ratio of the side opposite an angle to the hypotenuse in a right triangle: sin θ = opposite ÷ hypotenuse. It rises from 0 at 0° to 1 at 90°, making it the natural function for anything that swings between a minimum and a maximum — the height of a point on a rotating wheel, the vertical position in wave motion, or a simple physics projectile.
Worked example — ladder height
A 5 m ladder leans against a wall at 65° from the ground. The height it reaches up the wall is 5 × sin(65°) ≈ 4.53 m. Sine is the go-to function whenever you know a length and an angle from the ground and need the vertical component.
Key values worth memorising
| Angle | sin θ |
|---|---|
| 0° | 0 |
| 30° | 0.5 |
| 45° | 0.7071 |
| 60° | 0.8660 |
| 90° | 1 |
Questions people ask
What is sine in a right triangle?
It is the length of the side opposite the angle divided by the hypotenuse. On the unit circle it is simply the vertical coordinate.
Is anything sent to a server?
No. Every calculation runs in your browser, so nothing you type is uploaded and the page keeps working offline once it has loaded.
Last updated 17 August 2026