United States customary units mass: tower, apothecaries', troy, avoirdupois, and metric. Of these, the avoirdupois weight is the most common system used in the U.S., although Troy weight is still used to weigh precious metals. Apothecaries weight—once used by pharmacies—has been largely replaced by metric measurements. Tower weight fell out of use in England (due to legal prohibition in 1527) centuries ago, and was never used in the U.S. The imperial system, which is still used for some measures in the United Kingdom and other Commonwealth countries, is based on avoirdupois, with variations from U.S. customary units larger than a pound. The pound avoirdupois,
Weight for Age Age Advice U.S. Scale of Weights from about.com Weight for Age Weight for Age (WFA) is a term in Thoroughbred horse racing which is one of the conditions for a race. It means that a horse will carry a set weight in accordance with the Weight for Age Scale. This weight varies depending on the horse’s age, its sex, the race distance and the month of the year. Weight for age races are usually Group 1 races, races of the highest quality. It is a form of handicapping for horse racing, but within the horse racing industry is not referred