Are you wondering whether to travel in first class or second class? Sometimes the choice is made for you. Well, this is how certain factors determine whether you’re going to Eurail the first class way or the second class way.

If you're considering a Eurailpass or Selectpass: If you're 26 or older, you must buy a first-class railpass. Those under 26 have the choice of buying either a second- or a first-class pass. For two traveling together, a first-class Saverpass for two costs the same as one first-class adult and one second-class youth. Most families choose to keep youths together with them on a first-class Saverpass.

If you're considering a single-country pass: Most single-country and regional passes are available in second-class versions for travelers of any age.

If you're under 26: Some passes are discounted for youth traveling second class. To be eligible, you must be under 26 (according to your passport) the day you validate the pass in Europe.

If you're 60 or older: Even though some passes (Britrail, France) offer first-class-only senior discounts, you'll still save more by traveling in second class.

So how is first class different from second class?
First class cars generally feature bigger seats filled with business commuters and rail pass travelers over the age of 26 years.

Differences between first and second class: Normally, first class is configured with three plush seats per row (whether in compartment or open-style seating) and second class has four skinny, basic seats in the same space. Remember that nearly every train has both first- and second-class cars, each going at precisely the same speed.

Choosing first class: If you have the extra money, riding first class is less crowded and more comfortable. First-class rail passes can be a good value, too. While individual first-class tickets cost 50% more than second class, first-class rail passes generally bump your price up only 25% to 40%.

Choosing second class: If you're on a tight budget, second class makes lots of sense. In most of Europe, the new second-class cars are as comfortable as the old first-class ones.
 
Switching classes: Those with first-class passes may travel in second-class compartments (but why would you want to do that?). Those with second-class passes can pay the 50% difference in ticket price to upgrade to first (not possible in Britain).

Editor's Note: Get Eurail passes at the cheapest source of rail passes online: Rail Pass and Rail Europe