Realistically, When viewing a pic at 50% & 100% Photoshop?

For the A77 24 MP

I have a 24 in. Monitor. When I open up photoshop and bring the pic to a 50% view, what size would that be if I was looking at a printed photo? Same for a 100%

Also, What magnification should I use to realistically look at what a 11x14 print would like like printed? So in other words, Would magnification should I use to judge almost print quality?

Thank you in Advance.