03/01/2026
Q - Does a taller horse require a larger/wider bit?
A - Not always!
The most common bitting error I see is people with a horse over 16h using a 5.5" bit. Just because a horse is tall doesn't mean their mouth is wider. In fact, most of our modern sport horse types, TBs, STBs, WBs etc are quite fine from the facial crest down. Of course our heavy horse crosses can be a different story and due to their own confirmation being generally heavier we can often need a wider bit.
The main problem with having a bit that's too large in your horse's mouth is the communication can get fuzzy due to the movement of the mouthpiece of the bit over the sensitive tongue and bars (lower jaw). This much movement can also cause friction, rubbing and possible wounds both in the mouth and on the lips.
Just like your saddle fitting we need to take into account our horse's individual anatomy when we consider bit sizing and fit the horse, not the size of the horse.