Very often passengers are allowed one maximum legal carry-on size piece of luggage plus one personal item. The size for the MLC piece is usually given and sometimes even weight specs are given. However, the size or weight limit for the personal item are usually NOT given. What they do is they give examples like: purse, small backpack, briefcase, photo bag. A common sense definition has to be applied here. There are photo bags that are so big you could park a garbage truck in them and there are women that carry purses that are so big they could carry the kitchen sink.

What the personal item is basically defined as is an item that fits under the seat in front of you. That means two things. It means that this item should actually go there and not in the bin. So please keep the personal item personal and keep it at your seat and don't fill the bin with it. I've even heard that more and more from FAs recently. It makes perfect sense.

The second thing is that now, of course, we want to know: What fits under the seat in front of me?

There are two answers. A general guideline and a very specific answer.

General guideline:
Look for something that is not bigger than 17-18 by 11-12 by 8. You want to top out at around 36-38 linear inches.


Specific answer:
jaxbill had a very clever answer to this. I link his post here:
http://www.flyertalk.com/forum/13589659-post11.html

He says, look up the maximum hard shell pet carrier size that is allowed. They must be stowed under the seat in front of you. So these can differ from airline to airline and from plane to plane. In order to be sure you should do two things. 1. Call the airline. 2. Check on seatguru.com. They will tell you if the seat in front of you has an "entertainment box" installed under it. You don't want these seats if you want to maximize space.

Till