How do I measure my horse for a bit?

You can use a bit-measuring tool, which is a straight rod with measurements in inches, to see how the bit fits in the mouth. However, if you don’t have access to this tool, you can take a piece of string and mark the points on the string at the edge of your horse's mouth. Once you have this marked, measure the marks on a ruler, and you will have a general idea of what size bit your horse will need.

Note: Bit size can vary slightly, depending on design.