Rotation Calculator
Rotate a point about the origin by a given angle.
Rotate any point counter-clockwise around the origin by a chosen angle.
The math behind it
Apply the 2D rotation matrix: x′ = x cosθ − y sinθ and y′ = x sinθ + y cosθ.
Worked example
Rotating (1, 0) by 90° gives (0, 1).
FAQ
How do I rotate about another point?
Translate so that point is the origin, rotate, then translate back.