Inverse Cosine (Arccos) Calculator
Inverse Cosine (Arccos) Calculator
Arccos works the same way as arcsin, but for cosine instead of sine — rather than asking what the cosine of an angle is, it asks what angle has a given cosine value, and is also written cos⁻¹. Enter any value between −1 and 1, and this calculator finds the corresponding angle in both degrees and radians. Arccos returns its principal value between 0° and 180°, a different range than arcsin uses, reflecting how the two curves behave differently.
- Arccos (written cos⁻¹ or acos) is the inverse of the cosine function, answering "what angle has this cosine value?" rather than "what is the cosine of this angle?"
- Arccos only accepts inputs between −1 and 1, since cosine itself never produces a value outside that range — anything outside it has no real solution.
- Arccos returns a single angle between 0° and 180°, called the principal value, unlike arcsin which returns a value between −90° and 90°.
What does arccos actually calculate?
It finds the angle (within 0° to 180°) whose cosine equals the value you provide — the reverse operation of the cosine function.
What is arccos(0.5)?
60°, since cos(60°) = 0.5.
Inverse Cosine (Arccos) Calculator
Arccos works the same way as arcsin, but for cosine instead of sine — rather than asking what the cosine of an angle is, it asks what angle has a given cosine value, and is also written cos⁻¹. Enter any value between −1 and 1, and this calculator finds the corresponding angle in both degrees and radians. Arccos returns its principal value between 0° and 180°, a different range than arcsin uses, reflecting how the two curves behave differently.
- Arccos (written cos⁻¹ or acos) is the inverse of the cosine function, answering "what angle has this cosine value?" rather than "what is the cosine of this angle?"
- Arccos only accepts inputs between −1 and 1, since cosine itself never produces a value outside that range — anything outside it has no real solution.
- Arccos returns a single angle between 0° and 180°, called the principal value, unlike arcsin which returns a value between −90° and 90°.
What does arccos actually calculate?
It finds the angle (within 0° to 180°) whose cosine equals the value you provide — the reverse operation of the cosine function.
What is arccos(0.5)?
60°, since cos(60°) = 0.5.