It's not that straightforward to say as different measurements are used by different manufacturers and with a lot of bikes being the 'compact' type with sloping top tubes it makes it a bit of a minefield. Also everyone's anatomy is different so you can't base it on what someone else the same height as you has - they may have short or long legs - short or long back etc. You need to go along to a good bike shop and try the bikes. I see many customers who have bought the wrong size bike and then spend a fortune making changes to it to try and get it to fit - the problem being it is just not the right size. This especially so on internet buys.