Since most fat on the body is located directly under the skin, a very efficient and practical way to measure your body fat percentage is through skin-fold measurement, the scientific approach to the time honored "pinch an inch" method. Personal Body Fat Tester is a precision instrument that has shown in clinical trials to be closer in accuracy to the "gold standard" of underwater weighing then any of the more elaborate methods of measuring body fat (without the inconvenience, expense, trained personnel and lack of privacy these methods entail).