How to refactor this waterfall of ifs to be more clean and efficient?

I'm working on my flaw when i write code: i never write clean programs in any language.

So, any suggestion to re-write this piece of code in an "elegant" way? Because I don't like this waterfall of ifs...

public float RoundAngle(float angle)
{
    if(angle < 45 && angle >= -45){
        return 0
    }

    if(angle < 135 && angle >= 45){
        return 90
    }

    if(angle < 315 && angle >= 225)
    {
        return 270
    }
}