Thanks to The Tilt and Tack Shoppe for this useful information.
How much weight can a horse carry?
Twenty percent of its body weight in general. A horse in good shape and at proper body weight can carry approximately 20% of its body weight. That does not mean the rider can weigh 20% of the horse's weight. That means that the total or gross weight a horse can carry -- including rider, tack, costume, armor, etc. -- should not exceed 20% of the horse's own weight. That percentage should be reduced if the horse has a narrow build, especially if the horse is narrow in the muscles along the back. The percentage should also be reduced if the horse will be carrying weight (like armor) in front of the withers or behind the point of the hip.
What do you need:
- Bathroom Scale
- Equine Weight Measuring Tape
Weigh yourself dressed in your riding attire. Weigh all tack, gear, costumes, water bottles etc. that you will put on the horse. Add all of that up. Follow the directions on the Equine Weight Measuring Tape and estimate the weight of you horse. If you are unsure of your horses weight ask your horse care professional if the estimate is correct and if your horse is in proper shape (round is a shape but like humans not the best for horses).
My horse’s estimated weight is 1321 lbs. multiplied by .20 (20%) equals gross horse carrying capacity of 264.2 lbs.
1321 lbs. X .2 = 264.2 lbs. (horses maximum carrying capacity)
In this example if you and your gear weigh more than 264.2 lbs. you need to lighten the load or change horses.
Again, thanks to The Tilt and Tack Shoppe for this useful tip. Check out their online shop for other useful information as well as various equestrian products.
A few other methods for determining how much weight a horse can carry compiled by Randall Holman
Horse Science News: How Much Weight Can a Horse Carry?
Journal of Equine Veterinary Science: Evaluation of Indicators of Weight-Carrying Ability of Light Riding Horses