http://www.bestbuyhorsetack.com/bits/tack So how can you measure your horse to determine which will be the right size and therefore the most comfortable bit for them? When fitted correctly, the mouthpiece should extend each side of the lips to a measurement of approximately quarter of an inch. If it is too tight, the bit can end up pinching the skin when parts of the cheek move. Having it too long outside of the mouth is also considered to be a bad fit. Different styles of bits are available to best fit your horse!
