Luggage

That is up to the airline. When you book your ticket the airline provides baggage allowance information.

Are you checking luggage? Then it doesn’t matter. Carry-on only? Size and weight matter; check your airline’s restrictions. Taking trains? You have to manage your own luggage on and off the train. You also will have the schlep your luggage through terminals and to/from hotels. 21” works for me but weight matters which is a challenge.

It’s whatever the airline says.

"Should be" is kind of up to you going up to your airline's maximum and whether you carry on or check.

But Yes, I agree with Horsewoofie....if you are having to get in on/off trains you'll be managing it yourself. You may also need to carry it up and down stairs in a train station.

IF you are buying new luggage, I'd go with the 21" unless you are really strong! And yes, you can easily travel for 4-6 weeks or longer out of a 21" bag. It will take some work on a packing list and some dry runs on a trial pack to see what fits and what needs to be left at home. And yes, I also agree that weight matters.

Wheels and handle must be included in the measurement. Don't trust dimensions provided by the manufacturer, store or website; they often don't include wheels and handles, but airlines do.

Hi,

Here’s an example of the size restrictions for carry on. This one is Delta’s:

Individual length, width and height measurements may not exceed 22” x 14” x 9” (56 cm x 35 cm x 23 cm) respectively

If you are using something like Easy Jet, Ryan Air type planes, some of them may also have weight restrictions.

I really appreciate all this helpful feedback. Such a silly thing to be obsessing about. I’m thankful for the help you provided.

But keep in mind this often up to the discretion of a gate agent, there used to be cages where they would try and put your bag to see if it would fit. Sometimes that is still done but usually not. It's not unusual to hear from travelers who successfully get a bag onto one airline and then not another. Smaller is always better.

Also realize that if you are planning to carryon, so is everyone else and the overheads fill up quickly. If you're not up front in the plane, there might not be any room when you board.

That's one for the airline - and without knowing which, hard to say. If you are using internal UK flights you will see the measurements in centimetres