By Blake Jackson
Estimating hay bale weight is often a guessing game, which can lead to financial losses for both buyers and sellers, according to University of Missouri Extension forage specialist Rob Kallenbach.
“That’s because most folks think they know their bale weights, but more often than not, they’re guessing,” Kallenbach says. “And when you’re buying hay by the bale instead of by the ton, those guesses can cost you real money.”
Kallenbach notes that people often overestimate bale weights, sometimes by hundreds of pounds, during estimation exercises.
“Time and time again, we see folks overestimate bale weights, sometimes by a couple hundred pounds,” he says. “That can lead to errors of 15% to 20%, which is a pretty steep tax if you’re buying. Worse yet, it can lead to thinking you’ve got enough hay for the winter when you really don’t.” He attributes these inaccuracies to “neighbor talk” and the variability in bale density.
Factors like baler settings, forage type, moisture content, and storage conditions influence bale weight. “The reality is your hay bales might be shedding weight faster than a steer on Ozempic,” says Kallenbach. Newer balers tend to produce denser bales, further complicating estimations.
While scales offer the most accurate measurement, they aren't always readily available. Dennis Hancock, of the U.S. Dairy Forage Research Center, developed a method to estimate bale weight based on size and density.
Kallenbach explains how to judge bale density: loose bales depress easily (9 lbs DM/cubic foot or less); firmer bales give slightly (around 10 lbs DM/cubic foot); solid bales dent with pressure (about 11 lbs DM/cubic foot); and very dense bales are hard to penetrate (12 lbs DM/cubic foot or more).
Calculating bale volume is key to Hancock's method. Divide the bale's diameter (or height) by two, square the result, multiply by 3.14, and then multiply by the bale width.
For example, a 5-foot by 5-foot bale has approximately 98 cubic feet. Multiplying this volume by the estimated density provides an approximate bale weight. Though Hancock’s figures are estimates, they are more reliable than guesswork.
“It’s easy to misjudge bale weights, and those mistakes add up,” says Kallenbach. “Whether you’re buying hay or figuring out how much you’ve got stored for winter, a little math and a little common sense can go a long way toward making sure you don’t come up short.”
For more information visit, https://ipm.missouri.edu/croppest/2025/2/hay_weight-rk/
Photo Credit: gettyimages-pamwalker68
Categories: Missouri, Crops, Hay & Forage