Inverse trig calculator (arcsin, arccos, arctan)
Returns the principal angle, the same one a scientific calculator shows for sin⁻¹, cos⁻¹ or tan⁻¹.
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How to use it
- Enter inverse function and value.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
arcsin ranges over [-90°, 90°], arccos over [0°, 180°] and arctan over (-90°, 90°). arccsc x = arcsin(1/x) and arcsec x = arccos(1/x). Degrees = radians × 180 / π.
Example
Inputs: Inverse function = arcsin (sin⁻¹), Value = 0.5. Result: Angle in degrees: 30 °; Angle in radians: 0.5235987756 rad; Angle as a multiple of π: 0.16666667 π.
Limits and caveats
- Only the principal value is shown. Infinitely many other angles share the same value, found by adding full turns.
Questions about this tool
What is the difference between sin⁻¹ and 1 / sin?
sin⁻¹ is the inverse function and returns an angle, while 1 / sin is the cosecant and returns a number.
Why is there no arcsin of 2?
The sine of any real angle stays between -1 and 1.
How do I find every angle whose sine is 0.5?
The two in the first turn are 30° and 150°. Add or subtract 360° to either for the rest.