Some airlines advertise bigger seats or more legroom, but did you know that there are different space allocations within a single plane?
Consider pitch
Pitch is the distance between you and the seat in front and translates into legroom. In economy class, this can vary from 30 to a generous 34 inches. Those 4 inches can make a big difference in your comfort.
Air Canada has 33 to 34 inches in some aircraft (31 to 32 inches on some seats on its 747s and 767s). Many long-distance trains have a pitch of 51 inches, to compare.
Consider seat width
Most airline seats have remained 17 inches wide, even though North Americans have been getting larger. Compare this with the office chair cushions, which are usually 20 inches wide, and many train seats, which are 23 inches wide.
For long trips, ask the airline about pitch and seat width if your looking for comfort
Where NOT to sit
AVOID sitting at the rear or very front of the most economy cabins. You will be close to the lavatories or the kitchen or both, increasing traffic and odours. More importantly, the back seats may be narrower then the rest of the cabin (the plane is narrower at the rear), and these seats may not recline.
AVOID seats immediately in front of exit doors because they are often set in permanently upright positions to guarantee an easier emergency exit from the plane.
Where TO sit
Many travellers like the emergency exit rows because there is more knee room. These seats, however, often have immovable armrests. Also, travellers who choose these seats are required to help in an emergency. These seats are not assigned to people with physical disabilities or who are less than 16 years of age.