Next, decide what kind of hiking you plan to do on your snowshoes. Day-hikers carrying lighter packs will probably want smaller, lighter shoes. Your weight and the weight you are packing aren't the only things that determine the size of the snowshoe. If you hike forested trails, the snow under the trees is likely to be more compact and solid, so you can use a smaller 'shoe. Further, navigating narrow forest trails or brushwacking is not as easy if you're plowing along on a pair of shoes the size of the USS Enterprise.
Smaller snowshoes are preferable.
If you enjoy walking the high ridges and alpine meadows, you may find larger 'shoes the better choice. These provide greater flotation in the less consolidated snow of the high country. Shoes that provide greater flotation should be longer, not wider. Generally speaking, a 9-inch wide shoe is about all the average hiker will want. To get an idea of how walking on a pair of 9-inch wide 'shoes might feel, stand with your feet 18 inches apart.