Like most women, Tina Hines has her size — an 8 — and then she has her list of clothes that actually look good on her. Side pockets are out (they make her hips look too wide). Halter tops are difficult (she needs to wear a bra). Defined waists are good, and she likes a bit of Lycra to accentuate her curves.

Despite knowing all that, when she shops online, she is still flummoxed. The models are generally rail-thin and flat-chested — not like her. “Someone who’s an A-cup doesn’t help me, because it’s definitely going to lay a little bit differently,” said Ms. Hines, 44, a life coach in Franklin Park, N.J.

Now, for women like Ms. Hines, the e-commerce site Rent the Runway is offering a striking solution: replacing models with regular women, and allowing visitors to search for women of a certain age, height, weight and even bust size, to see how that dress looks on someone similar.

Think of it as crowdsourced sizing.

Rent the Runway’s new approach, which it introduced on Friday, is the latest example of a retailer rejecting the idea that women want fantasy when they shop. Instead, it is offering reality, catering to women who are fed up with Photoshopping, airbrushing and the headache of returning multiple sizes of clothing. The start-up Quincy offers clothes in different lengths, bust sizes and waist sizes. Me-Ality installs scanners in malls to match women’s bodies to mall brands. Clothes Horse sells retailers an algorithm and quiz so they can advise customers what size will fit in the retailers’ apparel.