Arccos(x) Calculator

Enter a cosine value between -1 and 1 to find the corresponding angle in degrees or radians.

θ = arccos(x) or θ = cos⁻¹(x)
arccos(0.5) = 60°

What is arccos?

Arccos (or inverse cosine) is the inverse function of the cosine. It is used to find the angle whose cosine is a given number. For example, arccos(0.5) is 60 degrees.

What is the range of arccos?

The standard range of the arccos function is from 0° to 180° (or 0 to π radians).

What is the domain of arccos?

The input value x for arccos(x) must be between -1 and 1 inclusive. If you enter a value outside this range, the result is undefined.