22/06/2026
Rider weight ratios are a wildly contentious subject - it's horribly easy to be accused of fat-shaming any time the topic is discussed.
But really, it's a matter of horse welfare. If you weigh a certain amount, you need to calculate what size of horse is needed to carry that weight with no adverse effects.
Speaking as a saddle fitter as well as a coach, it's also important if you are acquiring said horse to consider if it has the space on its back to accommodate a saddle of the size you need. Some of the heavy breeds have a surprisingly short bearing area!
The 20% calculation is based on old cavalry guidelines that horses should carry no more than 20% of their fit body weight. Note that the rider weight actually includes saddle, bridle, boots, helmet and other accoutrements that the horse has to carry.