Get measured by the professional who is selling you the bike. Every brand is different. Some brands had me listed as needing a 50-51 cm, but with TREK, I was listed as needing a 52 cm frame. I was also a candidate for women's specific designs for some brands, but with TREK, I didn't have to go that route. If you do have to get a WSD bike, make sure you can get the 54 cm wheels and not the 53.......you'll pedal harder to go the same distance and the bigger tires. That's just what was told to me. I love my TREK 1500 (2004 edition........check it out.......lots of bike for the money!). It fits me perfectly!

Kim in TN