One mile is 5280 feet, one foot is 12 inches. One square foot is 144 square inches, one cubic foot is 1728 cubic inches.
1 gallon of water is 8.34 pounds, and 1 cubic foot is 7.48 gallons, so a cubic foot of water weighs 62.38 pounds. If sand is 2.3 times heavier than water, a cubic foot of sand weighs 143.5 pounds.
I am 5 feet 10 inches tall, or 5.83 feet, or 70 inches. I weigh about 220 pounds, or 3520 ounces. If I’m 65% water, I carry about 143 pounds of water, or a little over 16 gallons.