I recently posted an article on the rules behind egress windows. I realize that knowing the rules doesn’t necessarily mean that you know the most common window sizes for each different window operation. So here are the basics and some links to the Anderson Window catalog as a guide:
Casement windows are minimally 2′-4″ wide by 3′-4″ high. For many casement windows you’ll need to order egress hardware which allows the window to not only swing open, but also swing away. Also remember that the sill can’t be more than 44″ above the floor so you may end up with a taller window for a head height over 6′-8″. Anderson’s Casement Sizes
Single or double hung windows are minimally 3′-0″ wide by 4′-8″ high or 2′-8″ wide and 5′-6″ high. I’ve seen a 2′-6″ wide by 5′-0″ high egress window but not all manufacturers make this window size. Anderson’s Double Hung Sizes
Slider windows are minimally 4′-0″ by 4′-0″. Again, watch the maximum sill height. Anderson’s Glider Sizes
I’ve included the links to the Anderson catalogs because they are very clear which of their windows allow for egress. Many manufacturers will call this out in their size charts. I’d suggest checking the specific sizes with the manufacturer that you intend to use and always specify which windows are intended for egress.