Hi, and thanks for being a FunFash customer! Our goal is to provide 5-Star satisfaction with your purchase. Our Store features clothing from over 30 different fashion designers, selling all over the world. So unfortunately there is no standard sizing. We get comments running small and large for the same exact size! We have, however, what we think is the best way to get it right for you the first time, quick and easy: Please refer to the measurements chart in the ad, then take your favorite top, and take the same measurements on it that we use in our ad. Compare your measurements to ours to make sure you get the correct fit. Save your measurements & use them time and again at Funfash! After doing the above measurements and you find you need to make changes to your order, please contact us immediately . We ship within 24 hours- please respond quickly if need be. Thanks very much