Inverse Trig Calculator

Find the angle whose sine, cosine, or tangent you know. Enter the value, function, and output unit.

Angle
—
That gives the value.

Usage Tip

Use inverse tangent on rise over run to get the angle of a slope or ramp.

THE MATH
asin, acos, or atan returns the angle for a given ratio
asin and acos require an input from −1 to 1
Inverse trig functions answer ‘what angle has this sine (or cosine, or tangent)?’
They are essential for finding angles in triangles from side ratios.
Inverse sine and cosine accept inputs from -1 to 1 only.
Inverse tangent accepts any real number.
Choose degrees or radians for the output.
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