Rotate UIView around its center keeping its size

You're probably hitting a problem with Autolayout. You probably have constraints on the rotated view pinning it to the edges of the superview. When the transform is applied, Autolayout is updating the view's size to still fit within the superview.

You can experiment with different constraints (e.g. pinning the centre of the view to the centre of another view, and pinning the width and height to constant values) or turn Autolayout off for the rotated view, or, if these don't work or don't suit your needs, use a container view which is laid out under Autolayout, and add your rotating view to this, without using Autolayout.

This can only be done in code - you can make individual views subject to Autolayout or not by setting translatesAutoresizingMasksIntoConstraints to NO (Autolayout on) or YES (Autolayout off). You'll need to set the appropriate autoresizing masks if you switch a view from one to the other.

I avoid using macros unless necessary. This works perfectly well

float degrees = 20; //the value in degrees
view.transform = CGAffineTransformMakeRotation(degrees * M_PI/180);

Swift + extension are your friends!!

// MARK: - UIView Extension
extension UIView {

    /**
       Rotate a view by specified degrees
       parameter angle: angle in degrees
     */

    func rotate(angle: CGFloat) {
        let radians = angle / 180.0 * CGFloat.pi
        let rotation = CGAffineTransformRotate(self.transform, radians);
        self.transform = rotation
    }

}

In this way, anywhere in your code:

let view = UIView(frame: CGRectMake(0, 0, 100, 100))
view.backgroundColor = UIcolor.redColor() 
view.rotate(angle:90)