Horse Weight Calculator

What this does

So you need to know roughly what your horse weighs, but there is no equine scale in the yard. This estimates it from a few measurements. Pick the horse type, measure the height, neck, girth, and body length, and it gives you two numbers, an estimate of what your horse weighs now and a rough ideal weight for its frame. Useful when discussing feeding, condition, or weight-based care with your vet.

How to use it

1. Pick the horse type, Arabian, pony, or stock horse.
2. Measure height, neck circumference, girth circumference, and body length, and enter each with its unit.
3. Tap Calculate to get the estimated body weight and the ideal weight, both in kilograms.

Use a soft tape measure, and measure the same way each time so you can track changes.

How it works

The numbers come from real research, a 2014 University of Minnesota study by Martinson and colleagues that measured hundreds of horses to build these equations. The useful part is that it uses the breed type plus four measurements, which is more accurate than the older formulas that used only girth and length. With every measurement in centimetres, the estimated body weight is:

weight (kg) = (girth^1.486 × length^0.554 × height^0.599 × neck^0.173) ÷ k

where k is 3596 for Arabians, 3606 for ponies, and 3441 for stock horses. The ideal weight uses a simpler equation:

ideal weight (kg) = (length × 2.8) + (height × 4.2) - c

where c is 611 for Arabians, 606 for ponies, and 577 for stock horses. Both calculations run on your device.

How to take the measurements

Getting the measurements right matters more than anything else, so here is where each one goes. Height is from the ground up to the withers, the ridge between the shoulder blades. Girth is the circumference right around the barrel, just behind the front legs and the withers, the same place a saddle girth sits. Body length is from the point of the shoulder to the point of the buttock. And neck circumference is measured around the middle of the neck. A flexible tape is best, and a second pair of hands makes the girth and length much easier.

Estimated weight versus ideal weight

You get two figures, and the gap between them is the telling bit. The estimated body weight is roughly what your horse weighs right now. The ideal weight is roughly what a horse of that frame should weigh in good condition. If the estimate sits well above the ideal, that points toward carrying extra weight, and well below points the other way. Helping owners spot that was a big reason the researchers built these equations, since judging a horse's weight by eye is notoriously unreliable. Treat it as a guide for conversations with your vet, not a diagnosis.

Questions people ask

References

1. Martinson, K. L., Coleman, R. C., Rendahl, A. K., Fang, Z., McCue, M. E. Estimation of body weight and development of a body weight score for adult equids using morphometric measurements. Journal of Animal Science, 2014. https://doi.org/10.2527/jas.2013-6689