Horse Weight Calculator
Estimate equine body weight in pounds and kilograms using heart girth and point-of-shoulder to point-of-buttock measurements.
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The Carroll and Huntington Equine Weight Formula
Livestock weigh scales are rarely accessible at private horse barns. Equine nutritionists and veterinarians calculate body mass using the scientifically validated Carroll & Huntington biometric equation:
Weight (lbs) = (Heart Girth Inches² × Body Length Inches) / Divisor
The standard divisor is 330 for adult mature horses, 301 for yearlings, and 280 for weanlings. Measuring body length alongside girth improves accuracy over commercial weight tapes (which measure only girth) by more than 8% to 12%.
Frequently Asked Questions
Where do I measure heart girth on a horse?
Place a flexible tailor tape snug around the horse directly behind the front elbow joints, passing up and over the highest point of the withers while the horse is standing square on level ground.
Where do I measure body length?
Measure from the prominent point of the shoulder at the front of the chest diagonally across the barrel to the point of the buttock (tuber ischii) below the dock of the tail.
How much forage should a horse eat per day?
An adult horse requires 1.5% to 2.5% of its body weight in dry forage daily (typically 20 to 25 lbs of hay for an average 1,000 to 1,100 lb horse) to maintain healthy gut motility and prevent colic.