Most sample gowns in bridal stores are a medium-to-large size, so everyone can try them on. Unless buying off the rack, you'll need to order the gown in your size; then, slight alterations can be made, for a custom fit. Typically, you'll go in for several fittings over several months. Try to envision how you'll be moving in the gown, not just how it feels standing still. Is it comfortable enough for sitting as well as dancing? Does it stay in place, or always seem to be slipping off a shoulder? Don't put unnecessary pressure on yourself by getting a gown that's too small, thinking you'll lose weight to fit into it. It's better to get one that fits now. If you lose, you can always have it taken up. But by the same token, don't start out with a gown that's way too big. The cost of alterations can be enormous, and after a point, the look of the dress is compromised. Be wary of shops that encourage you to buy a dress much larger than your normal size. If they tell you the sizes are different for bridal gowns, ask to see the manufacturer's sizing chart. Compare it to your own measurements, and choose the size accordingly.