You can check your standover height right from home!
Here's what you'll need.
Grab a pen, a large book, your tape measure, and head over to the closest wall. Stand flat-footed with your back to the wall, place the book between your legs and press it up underneath you like a saddle. Make sure the book’s level (a friend can help with this) and make a mark on the wall where the book meets it. Now take your tape measure and check the distance from the mark to the floor, that’s your standover height!
You can find the standover heights of the various frame sizes on the bikes’ spec pages. Just look for one that gives you the right amount of clearance based on your newfound number! (For example, your standover height is 33", look for bikes with a standover height of ~32").