1. Definition

Waist width is the narrowest part of a snowboard, located between the bindings—directly beneath your boots. 

It is typically measured in millimeters (mm).

 “Waist Width refers to the narrowest point of a snowboard, located between the bindings.” 

— Burton Snowboards Glossary [1]

 The waist width is a key factor in determining how well a snowboard fits your boot size and riding style.

2. How It’s Measured

Waist width is a fixed measurement that is usually provided by the manufacturer. To measure it manually: 

2.1 Lay the snowboard flat.

2.2 Use a ruler or caliper to measure the narrowest part of the board (typically underfoot, between the inserts).

2.3 The value is recorded in millimeters (e.g., 255mm).

 “Snowboard dimensions such as waist width are typically provided by the manufacturer, measured at the board's narrowest point between the bindings.” 

— REI Expert Advice: How to Choose a Snowboard [2]