Bales of hay vary in size from 40 to 2,000 pounds. A three-string bale weighs around 100 pounds, and there are approximately 20 three-string bales in a ton. Round bales weigh 850 to 1,100 pounds, and there are 2.4 to 1.8 round bales per ton.
Hay is also sold in 1-ton bales, with a single bale per ton. A standard three-string bale weighs around 140 pounds and breaks into 17 flakes, each weighing about 8 pounds. Small bales, called two-string bales, weigh only 40 to 75 pounds each. The best quality hay is baled into three-string bales, and over-mature hay is baled as round bales.