A hay bale can weigh a wide range depending on its size, shape, moisture, and the type of forage. Here are typical weights you’ll commonly encounter:

• Small square bales (about 14x18x36 inches): roughly 40–75 pounds (18–34 kg) for standard, loosely packed varieties; higher-density or multi-wire small bales can reach about 100–180 pounds (45–81 kg) depending on packing.
• Large square bales (about 3x4x8 feet or 4x4x8 feet, depending on region): typically 800–1,500 pounds (360–680 kg), with heavier density bales toward the upper end.
• Large round bales (common in pasture systems): often around 1,000–1,500 pounds (450–680 kg), though diameter, width, and moisture can push values outside this range.

Key factors that influence bale weight:

• Forage type: Legumes like alfalfa are generally denser and heavier than grasses such as timothy or Bermuda grass.
• Moisture content: Higher moisture adds weight; optimal storage moisture is usually around 15–20%, but baling at different moisture levels changes weight.
• Density and compression: Tighter packing increases weight per bale for the same external dimensions.
• Bale dimensions: The standardization of bale sizes varies by region; weights scale with bale volume.

If you have a specific bale size (for example, “3x3x8 large square” or “5x5 round bale”) and a forage type, I can give a more precise weight estimate for that combination.