7 grams.
A roll of the current CN clad quarters weighs 226.8 gm. A roll of the old 90% silver quarters weighs 250 gm.A roll of 40% silver bicentennial quarters would weigh 230 gm.
dated 1965 and later each quarter weighs 5.67 grams so 2000 quarters X 5.67 = 11340 g = 25.0004 lb
1 KG = 2.2 bls do the math!
This will vary with build, age, sex, and workload etc. But typically a Quarter horse will weigh between 850-1500 pounds.