Sizing Guide: How to Measure Your Bit Accurately

4 min.

When choosing a bit, there are several measurements to consider, including length, thickness, ring size, and design.

Loose Ring Bits The following measurements are important to consider when choosing a loose ring snaffle or similar bits like Universal, Beval, Balding Gag:

  • Mouthpiece Length: Measure the length of the bit from the inside of one ring to the inside of the other when the rings are pulled apart to their maximum length. This can be measured in inches or centimeters.
  • Mouthpiece Thickness: Measure the diameter of the mouthpiece next to the cheek, just before the hole for the ring. This can be measured with a tape measure or a set of calipers for greater accuracy.
  • Loose Ring Diameter: Measure the inner edge of the loose ring in millimeters. The standard size for a loose ring is 70 mm and the average bridoon size is 55 mm.

Fixed Cheeks

The following measurements are important to consider when choosing a fixed cheek bit like Baucher, D-Ring Full Cheek, Eggbutt, Pelham, NS Jumper, Cheltenham, Nelson, or Weymouth:

  • Mouthpiece Thickness: Measure the diameter of the mouthpiece next to the cheek.


When choosing a Weymouth bit, consider these additional measurements:

  1. Shank Length (Lower): Measure the length of the shank below the mouthpiece to the bottom of the shank in centimeters (5 cm, 7 cm, 9 cm options available). The legal length for FEI Dressage is 10 cm.
  2. Shank Length (Upper): Measure the length of the upper shank, which must not exceed the length of the lower shank according to FEI Dressage rules.

Waterford Mouthpiece Range

Due to its unique LipSMART™ design, use the same sizing as your current bit for a Waterford mouthpiece. If changing from a loose ring to a fixed cheek, downsize by ¼ inch, and if moving from a fixed cheek to a loose ring, increase by ¼ inch.

Verbindend Mouthpiece

Range The uniquely shaped cannons of the Verbindend mouthpiece may require a size increase of ¼ inch for proper fit.

Turtle Top and Turtle Tactio Range

These bits are measured differently due to their shaped cannons. Refer to the sizing guide for measuring instructions.

Mouthpiece Sizes Neue Schule traditional mouthpieces come in sizes ranging from 4″ (101 mm) to 6.5″ (165 mm). The table below shows imperial/metric conversions.

Imperial (inches)
Metric (mm)101107114120127133140146152159165

Cheek Sizes

The size of the cheek depends on the cheek style. The table below lists the variations.

Cheek TypeVariations
Loose Ring45mm, 55mm, 65mm, 70mm
Weymouth5cm, 7cm
Pelham5cm, 7cm


How do I go about measuring my loose ring mouthpiece thickness, length and ring size?


There are various measurements to consider when sourcing and assessing the correct size of bit including length, thickness, ring size and design.


The picture below demonstrates a popular loose ring snaffle, the NS Team Up (9012). Other cheeks that are measured this way include the Universal, Beval and Balding Gag and the measurements to consider here are:

  1. Mouthpiece Length: The measurement is taken by placing the bit on a flat surface and pulling the rings apart so the bit is at its maximum length. The measurement is taken along the full length of the mouthpiece from the inside edge of the loose ring to the inside edge of the opposite loose ring and can be measured in inches or centimetres.
  2. Mouthpiece Thickness: This measurement is taken at the widest part near to the cheek just before the hole that the ring slides through. Again, if you put the bit on a flat surface, you can slide a tape measure below this point and, if you look from above, you can see the thickness. The most accurate way to measure the thickness is using a set of calipers, which are widely available.
  3. Loose Ring Diameter: This measurement is taken from the inner edge of the loose ring and is generally measured in millimeters; 70mm being the average for a standard loose ring; and 55mm the typical bridoon size.

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