How much does Sheetrock weigh?

According to United States Gypsum (www.usg.com), standard drywall weighs about 3.4 lbs per sq ft per inch thickness. Water resistant drywall (greenboard) weighs about 3.9 lbs. per sq. ft. per inch thickness. Firecode C drywall weighs about 4.2 lbs. per sq. ft. per inch thickness. These are approximations, as the ratio of core vs. covering varies for different thicknesses, thereby varying the exact weights. So, 1/2" thick standard drywall weighs 3.4 x 0.5, or 1.7 lbs per sq. ft. 4' x 8' x 1/2" thick sheet weighs 1.7 x 32 s.f. = 54 lbs. 4' x 10' x 1/2" thick sheet weighs 1.7 x 40 s.f. = 68 lbs. 4' x 12' x 1/2" thick sheet weighs 1.7 x 48 s.f. = 82 lbs. 5/8" thick standard drywall weighs 3.4 x 0.625 = 2.2 lbs per sq. ft. 4' x 8' x 5/8" thick sheet weighs about 70 lbs. 4' x 10' x 5/8" thick sheet weighs about 88 lbs. 4' x 12' x 5/8" thick sheet weighs about 105 lbs.