The resistance the current encounters as it travels depends on the proportion of fat and muscle tissue. That tiny current-much too low to feel or cause any harm-passes up one leg, through your pelvis, and down your other leg. The scales we tested measure body fat using an electric current that travels through your body when you step barefoot onto the device’s metal footpads. (Research shows that method is as accurate as the other gold standard-measuring how much water a body displaces when dunked into a tank full of water-but the Bod Pod measure is quicker and easier to perform.) The egg-shaped device determines body fat by precisely recording the change in air pressure created when a body is sealed into a closed chamber. Six volunteers-three men and three women, some heavier, some slimmer-climbed into the Bod Pod. We know that because we got benchmark readings by using a measuring tool called a Bod Pod at Sacred Heart University in Fairfield, Conn.

Rating a body-fat scale on its ability to gauge body fat was more complicated, and the results were unimpressive: None was very accurate. Customers can ask for a refund or replacement at (For more details on all six scales, check our Ratings and buying guide.) Consumer Reports investigated Qardio's fix here's what we found. When we asked Qardio to respond to our findings, the company told us that it was aware of the problem and said it was corrected. To do that, we had seven men and eight women step on an electronic lab scale, which we used as a control, then weighed them four times over two days on each of the scales.įive of the body-fat scales read weight accurately, but one, the Qardio QardioBase (which happened to be one of the priciest), routinely overestimated weight by 6 to 10 pounds. We checked first to see how well they performed the most basic function: giving users an accurate weight. We looked at six digital scales that gave readings for weight and body fat (some calculate BMI as well), ranging in price from $40 to $150.

Accurate 5 inch scale