Rugs are generally measured in feet and inches.  To measure your horse for a rug, as an approximate size guide, you can measure from the centre of their chest right around the horse to the back of their rump.  However whilst this will give you a rough idea, some rugs and brands will vary in size and fit so it is wise to check with the manufacturers or your retailer who should be able to guide you.

A rug should fit comfortably along the length of the horse, whilst allowing plenty of room for freedom of movement through their shoulders.  Shoulder gussets tend to be important to ensure your horse can move freely through the front of their rug when galloping across the paddock.  By the same token, care must be taken to ensure a rug is not overly large or too cumbersome, that it gets in the way of the horse. Ensuring a rug is correctly fitted is essential, particularly if your horse wears his rug almost 24/7 out in the paddock, as their safety and comfort will depend on it.

Fittings, such as buckles, straps and clips should be approached with care.  When purchasing a rug, always go for the strongest buckles and clips that you can, as these tend to be a rugs biggest weakness and will often break.  When adjusting straps and buckles, always ensure they are snugly fitted against the horse, whilst allowing them the full range of necessary movement.  For example, chest straps should be tight enough to safely hold the rug and ensure the horse can't remove or get tangled in their rug, whilst ensuring they can still move their front shoulders and legs freely, and they can put their heads down comfortably to eat without the straps cutting into the underside of the neck.  Leg straps should be approached with similar caution to ensure the horses back legs can't get tangled yet don't cut in to their legs.  Once an initial fitting is completed, regular checks should be conducted to ensure rubbing is prevented and that straps don't work themselves dangerously loose.

Approximate Rug Size Guide

Rug Size (Feet) Rug Measurements (CM) Horse Height (Hands)
4'0  122 Under 9 hands
4'3  130 9 - 10.2
4'6  137 10.2 - 12
4'9  145 12 - 12.2
5'0  150 12.2 - 13.2
5'3  160 13.2 - 14
5'6  168 14 - 14.2
5'9  175 14.2 - 15
6'0  183 15 - 15.2
6'3  190 15.2 - 16
6'6  198 16 - 16.2
6'9  207

16.2 - 17