Knowing your horse’s weight is important when designing a feeding program and also for administering supplements or medications such as bute, banamine, or dewormers. The problem is that most of us don’t have a horse-sized scale on hand!
Many people tend to estimate that their adult horse is about a thousand pounds, but, of course, this can’t be true in every case. For example, an adult Quarter Horse may weigh anywhere from 900-1300 lbs. An adult Warmblood, by contrast, usually weighs between 1200 and 1450 lbs. Arabian or lighter horse breeds would weigh less.
The good news is that there is a fairly easy method for estimating your horse’s weight; all you need is a flexible measuring tape (such as the kind a seamstress would use), a little knowledge of horse anatomy, and some basic math skills.
Here’s what you will need to do exactly:
1.) With your horse standing still and square, measure his body length, that is, from the point of shoulder to the point of buttock (furthermost bony point high on the buttocks, near the tail).
2.) Then measure your horse’s heart girth, the circumference of the chest just behind the withers and elbow.
Note: you may want to take each measurement at least twice to ensure that it is accurate.
3.) Finally, using pencil and paper or a calculator, plug your measurements into one of the following formulas:
(Heart girth2 x Body length) / (330) = weight in lbs.
(Heart girth2 x Body length) / (11,880 cm3) = weight in kg
And voila, you should now have a fairly close estimate of your horse’s actual weight. One thing to keep in mind, however, is that a horse’s weight can fluctuate from season to season, so you will likely want to re-measure and estimate your horse’s weight at least a couple times a year and change your feeding regimen accordingly.
Final note: the above formulas aren’t intended for miniature horses or growing horses, but will work well for most large breed adult horses.
If you’ve already used this method to estimate your horse’s weight, feel free to share about the experience in the comments below!