Big Feet

• One of the most straightforward reasons for having a wide snowboard is that the rider has big feet. If the toes or heels hang over the edge of the snowboard too much, then they may dig in to the snow, instead of the edges, making it very difficult to turn. When shopping for a snowboard, it's important to get a snowboard that's wide enough if you have long feet.
  
  

Deep Side Cut

• Snowboards have a fairly uniform shape in the tail and nose sections. The main width differences, when they aren't related to foot size, are found in between the tail and the nose. This is called the side cut. A deep side cut, or a relatively narrow snowboard, will give the snowboard rider more control in turns. This can be an advantage when there's a large amount of fresh snow, for instance.
  
  

Shallow Side Cut

• A shallow side cut, which would be a wider snowboard, will be detrimental to the turning abilities of a snowboard rider. The benefit of a wider snowboard, however, will be increased surface area for contact with the snow. This increase in surface area is a big determinant in the speed of a snowboarder. A wider snowboard will mean that the rider goes faster.
  
  

Length

• Another important dimensional variable is the length of the snowboard. Just like width, length is in part determined by the size of the rider. A longer snowboard will also increase the surface area of the snowboard, just as a wide snowboard does. This will, again, translate into a faster trip down the hill. So if you want to go fast, you should take both width and length into consideration.