I almost always travel with just a backpack,a regular sized one with a laptop sleeve. It's pretty full, but not stuffed full because I usually take my laptop out and put it in the seatback pocket. But it's got a few days worth of clothes, and other things. It always fits fine under the seat.

I recently traveled with a school group. We directed the kids to bring carry ons, and their backpacks, and everyone's backpack fit under the seat.

My kids always bring backpacks plus carry on suitcase domestically and internationally with no problems. The packs aren’t stuffed full. If you want a sweater for the plane and are concerned it will push your backpack to the iffy zone, you can always just tie it around your waist until you board.

That North Face backpack answer is absolutely correct. I’ve been all over the world with this same exact pack as a personal item and it’s always fine.

Anonymous wrote:https://www.thenorthface.com/shop/recon-nf0a3kv1#hero=0

I have this backpack and have used it on probably 250 United flights in the past few years. No issues.

I should add that I usually just have my laptop, some snacks, a water bottle and maybe a sweater in there so it fits easily under the seat. If it were stuffed full, it wouldn't fit under the seat and thus not qualify as a personal item.

Anonymous wrote:It’s gotta fit under the seat. Don’t go trying to put two items overhead.

This--the "personal item" should fit under the seat, so the precise dimensions are less important that how stuffed it is.

https://www.thenorthface.com/shop/recon-nf0a3kv1#hero=0

I have this backpack and have used it on probably 250 United flights in the past few years. No issues.

It’s gotta fit under the seat. Don’t go trying to put two items overhead.

I’ve never had trouble with slightly oversize daypacks but it seems that the airlines are sometimes sticklers on this point. It’s a risk.

I often have a standard LL Bean backpack as my under-swat personal item on Southwest, United and Delta.

Big backpack is carry on, not personal item.

So we are flying United in a few weeks and it says we are allowed a personal item of 17x10x9 plus a carry on as a Economy Plus passenger. It mentions backpacks as an example of a personal item. However, my very common backpack and even my son's soccer backpack are 19x12x9. Does anyone ever have a hard time with their backpack being too big? Thanks.