UNFILLED EXPECTATIONS The manufacturer of this GE Profile PSB42LSR[BV] refrigerator claims its holds 25.2 cu. ft., but we measured its usable capacity at only 16.6 cu. ft., a difference of more than 34 percent.

Manufacturers tend to boast about the capacity of their refrigerators, with some models from our latest tests touted as having as much as a 27-cubic-foot capacity. The companies arrive at those figures by counting every nook and cranny, but as our tests have found over the years, the claims often don’t measure up.

As a requirement for the EnergyGuide label, manufacturers calculate volume by measuring the height, length, and width of every part of a refrigerator box and totaling the results. Makers include the space occupied by shelves, hardware, and the indentation where you fill a glass with water and/or ice. They could recalculate volume based on realistic use, but they don’t. For example, the $6,200 GE Profile PSB42LSR[BV] built-in side-by-side (shown) we tested has a claimed capacity of 25.2 cubic feet, but we measured usable space at 16.6 cubic feet.

“When we list capacity, that’s a standard measurement from the Association of Home Appliance Manufacturers,” says Greg Garavalia, senior product manager for refrigeration for Whirlpool. “All the manufacturers are using the same methodology because it directly impacts energy consumption.” Garavalia says that otherwise, each manufacturer would have a different standard for usable capacity, and consumers would be left comparing apples with oranges.

Our recent tests indicate that the biggest difference between claimed and usable capacity occurs in side-by-sides. On average, the usable capacity is 35 percent less than the claimed. For top-freezers, the usable capacity, on average, is 21 percent less than the claimed. Bottom-freezers show a 31 percent difference, and for built-ins, the average difference is 32 percent.

The best way to find the usable space in a refrigerator is to refer to the measured capacity for each model in our Ratings (available to subscribers) for top-freezers, bottom-freezers, side-by-sides, and built-ins. You’ll also find basic shopping information in our buying advice.  And don’t miss our latest refrigerators report.