<prompt> Average weight of spleen in adult:5 ounce7 ounce14 ounce21 ounce  <response>: Ans. B 7 ounceRef: BDC, 6th ed. vol. II pg. 294 On an average the spleen is 1 inch or 2.5 cm thick, 3 inches or 7.5 cm broad, 5 inches or 12.5 cm long and 7 ounces in weight.Some Must Know Weights Weight of liver: 1.5 kg. Weight of thyroid gland: 25 gm Weight of prostate: 8 gm. 