Sizes and Shapes of the Duplo Horseshoe
The size of a Duplo Horseshoe is always measured at its widest point. The smallest Duplo is 98 mm wide, the largest one is 170 mm. The interval between sizes is 4 mm - you will therefore find models of 110 mm and 114 mm but nothing in-between. If your horse needs an in-between size, you can easily adjust a slightly too large horseshoe with an angle grinder.
Duplo Horseshoes are not only available in numerous sizes but also in two different shapes. The round horseshoes generally fit the front hooves, the oval models are rather made for hind hooves. As always: The exception prooves the rule.
To determine the correct Duplo size for your horse, it should be unshoed. The hoof should be correctly trimmed so that a new horseshoe could be applied. If you measure an untrimmed or shoed hoof, you might not get the desirable exact results.
First, use a measuring tape or a ruler to measure the widest point of the hoof's lower surface which usually is to be found at a short distance behind the frog apex.
Then, take a look at the sole as a whole and decide whether it is rather round or oval.
With these two results - the hoof width in millimeters and the hoof shape - you can choose a Duplo model in your horse's size.