I have a small cafetiere for making French Press coffee. I can't remember what it said on the box when I bought it - it's quite old - but it seems similar to those advertised as '2-cup' size.
Making coffee with it, filling it all the way up, makes a decent mugfull - what I'd consider enough for one person. Is this actually two 'servings' of french press? When I calculate how much caffeine I'm taking in, should I double the values given for French Press?