Originally Posted by artemis

Hear, hear! A standard Economy Class seat width across all airlines would also make it easier for someone who's heavy (but not 400 lbs) to know in advance if they will actually fit in the seat. With economy class seat widths varying as much as they do, right now for the average person it's a guess (because they don't know about Seat Guru, and because equipment changes are a Thing). I don't want to buy a second seat because I thought the economy class seat on flight 1234 was going to be 16.8" inches wide, only to discover that in fact it's 17.5" or 18" wide and I fit it just fine. I also don't want to squish my fellow passengers because I guessed wrong.