How to Measure a Bit

Measuring your bit properly is paramount to ordering the proper bit for your horse!

The photo below shows how to measure from inside the cheekpiece to the opposite cheekpiece.

This is a 4.75" Bowman Bean Link Snaffle.

Measuring your horse's mouth is also important to using the correct size bit. There are a number of ways to accomplish this, but a handy tool to use is our Bit Sizer.

A great benefit of using a mouth measuring tool is that it can measure the sides of the horse's face, which, especially on smaller horses, can widen quite dramatically above the mouth. Our gelding below has a mouth measurement of 4". However, he has "fleshy" lips that "widen" when the bit is in. To compound that, he goes well in a Butterfly bit with a purchase, the "stem" above the mouthpiece where you attach the bit to the headstall. Even though most good curb style bits have the purchase bent out as you can see below, this still creates a point where the leather can get tight on the horse's face. Having a wider bit can alleviate this issue. Alax's bit below is a 4.5". Notice how it is a little "sloppy" at the mouth, but gives him room at the point of attachment to the headstall. Judges have noticed how his bit is a little big, but also comment that he goes well in it and haven't faulted us for it. The comfort of the horse is definitely important when choosing a bit size!

Some bits can come in different sizes of mouthpiece diameters.  Diameter is the measurement across a circle, not to be confused with circumference, which is the measurement around a circle.  Here is how you measure mouthpiece diameters with a caliper:

This is an imported bit, so the mouthpiece is actually made with a metric measurement.  This mouthpiece measures 15 mm.  It is not quite 5/8". 


Bowman Bits can be custom built in 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", and 3/4" (Hollow mouthpieces) diameters.  The Bowman Bits we stock are in typical diameters for that width bit.