Is a 2-person tent actually big enough for two people?
Short answer
For sleeping, almost always. For anything else, often not. A two-person tent gives each person 13 to 17 square feet, which is a sleeping pad and about a forearm of spare floor. Gear lives in the vestibule, not inside.
Where the number comes from
Capacity is how many standard sleeping pads a maker can lay side by side with nothing else in the tent. It is a packing measurement, not a comfort one, and there is no standard behind it — one brand's two-person tent is 27 square feet and another's is 33.
Divide floor area by capacity and the marketing collapses into something you can act on. Under 14 square feet each, two adults are shoulder to shoulder and nothing else fits. Fourteen to 17 is the normal fit: two pads, a pair of boots, no spare floor. Over 17 and you can bring both packs inside and still sit up without leaning on somebody.
Width is the binding constraint, not area
Two 25-inch pads need 50 inches of floor. A lot of two-person tents are 50 inches at the shoulders and taper to 42 or 45 at the foot, which fits the pads where your heads are and pushes them into each other at your feet.
If one of you is on a 20-inch pad the problem disappears at a stroke, and a 43-inch tapered foot stops mattering. It is worth knowing which case you are in before you pay for the wider tent.
The sensible workaround
Buying the three-person version of a two-person design is the most common answer, and on the numbers it is a good one: three-person tents typically add ten to fourteen square feet for six to ten ounces, which is a better rate than almost anything else you can spend weight on.
The other direction works too. A two-person tent used solo is a genuinely luxurious solo tent — 28 square feet to yourself, with room for a pack, wet boots and somewhere to sit out a rainy afternoon.
Tents this comes up with
Durston
Durston X-Mid
16.6 sq ft each
Nemo
Nemo Dagger OSMO
15.3 sq ft each
Big Agnes
Big Agnes Copper Spur UL
14.5 sq ft each
More of the same kind of thing on tent specs, explained, or start from a filtered list.