Estimating Your Horse's Weight

Being able to weigh your horse from time to time not only helps you monitor his body condition for overall health, it’s also important when developing a feeding program and calculating appropriate dosages for dewormers and medications. Unfortunately, your bathroom scale doesn’t stand a chance under the 1200 or so pounds of the average horse. A livestock scale typically provides the most accurate measurement of a horse’s weight, but this equipment is not available at all large animal veterinary clinics. In this case, there are two primary alternatives – the standard equine body weight formula or a weight tape.

Using the Equine Body Weight Formula
Calculating your horse’s body weight using the following formula is generally considered to be a more accurate method than a weight tape, and requires only an ordinary soft measuring tape.

Weight (kg) = [heart girth (cm) x heart girth (cm) x body length (cm)] / 11,990

The heart girth of the horse is obtained by measuring the circumference of the horse’s midsection just behind the elbows and withers.

The body length of the horse refers to the measurement from the point of the shoulder straight back along the horse’s side to the point of the buttock. Measuring the body length of a horse will require two people.

Plug your values for heart girth and body length into the equation to calculate the weight of your horse in kilograms.

Using a Weight Tape
Available at most tack and feed stores, weight tapes, which are essentially soft measuring tapes calibrated in pounds and/or kilograms instead of inches, can be purchased in pony, horse, and draft sizes. While quick and easy to use, it should be noted that a weight tape will not always generate an accurate result for pregnant mares, foals, miniature horses, and significantly overweight or underweight horses. In these situations, other weight estimate resources should be utilized.

Step 1: Equipped with a weight tape specific to the size of equine you are weighing, begin with the horse standing squarely on a flat surface.

Step 2: Position yourself at the horse’s left shoulder and anchor the starting end of the weight tape with your hand just behind the withers of the horse with the tail of the tape draping down on the horse’s right side.

Step 3: Carefully, reach under the horse’s belly to grasp the tail end of the tape, pulling it up and around behind his elbow as you would a girth to meet the starting end. Correctly adjusted, the tape will be snug, but not overly tight, and lying flat and untwisted against the horse’s side with the two ends meeting on a slightly diagonal angle.

Step 4: Note the weight measurement that occurs at the point where the two ends of the tape intersect.