Calculate the sine of an angle, or find the angle from a known sine value.
How to Use the Sine Calculator
Switch direction with the toggle: an angle in for the sine value, or a known sine value in to solve for the angle.
sin(θ) = opposite ÷ hypotenuseIn a right triangle, that's the whole definition — the side opposite your angle, divided by the hypotenuse. This Sine Calculator extends the same ratio beyond triangles to any angle at all, and runs it backward too: give it a sine value and it'll return the angle (arcsin) that produces it.
The opposite side can never outgrow the hypotenuse, geometrically, which is why sine never leaves the −1 to 1 range — and why arcsin refuses anything outside it. Set the angle mode before you start: sin(30°) is a tidy 0.5, but sin of 30 radians is a different number entirely, since radians and degrees carve up a circle differently (360° versus 2π).