What size bike should I ride?

Bike sizing is not an exact science, but a general rule of thumb is as follows:

Recommended Bike Sizes

Your Height Your Inseam Length Bike Frame Size
5'3" and shorter 27" and shorter 15 inch
5’3" - 5'7" 27" - 30" 17.5 inch
5’8” and taller 30” and taller 20 inch

Remember that the bike seat is adjustable.  Seat height should allow your knee to have a slight bend when extended. If your knee is fully extended, the seat should be lowered.