Two different measurements
Saddle size really involves two separate questions that work together: the seat size, which is mostly about the rider, and the tree width and fitting, which is about the horse. A saddle can only be right when both suit at the same time, which is why size is best confirmed through proper remote saddle fitting rather than guessed from a chart.
This guide explains the principles. It is general information, not a final recommendation for your horse and rider.
Seat size: fitting the rider
Seat size is measured in inches and describes the length of the seat. As a rough guide, a larger or taller rider usually needs a larger seat, and a smaller rider a smaller seat. The right seat should let the rider sit centrally with a comfortable hand’s width or so behind the seat at the cantle, without being perched or swimming.
However, seat size cannot be chosen in isolation. On a short-backed horse there may be a limit to how long a saddle the back can carry, so the rider’s ideal seat size sometimes has to be balanced against the horse’s length. Discipline matters too, as dressage, jumping and general-purpose saddles are cut differently. We discuss this further on our short-backed horses page.
Tree width and gullet: fitting the horse
Tree width describes how wide the front arch of the saddle is, and it must match the angle and width of the horse’s back just behind the shoulder. A tree too narrow can pinch; a tree too wide can drop the front of the saddle down onto the wither and tip the rider forward.
Width is not simply narrow, medium or wide across all brands; fittings vary, and the panel shape matters as much as the bare width. This is why we rely on a back template taken at the correct point, supported by photographs, rather than a single label.
Why both must work together
A saddle that fits the horse but is the wrong seat size for the rider, or fits the rider but is too wide or long for the horse, will not work well. The aim is a saddle that balances both. For horses or riders who fall outside standard combinations, IDEAL’s Designed to Order service allows seat size, width, flap and balance to be specified together.
A cautious note
Sizing guidance is a starting point, not a substitute for assessment. Horses change shape, and small differences in panel and balance affect how a saddle sits. Any sign of discomfort requires assessment and is not a substitute for veterinary advice.
Let us confirm the right size
The most reliable way to find your size is to send a template, photographs and the rider’s details so we can advise on the combination that suits. Use our remote fitting checklist and see how it works.
When you are ready, start your remote fitting enquiry and we will help you confirm the right saddle size for both horse and rider.