Rain resistance is measured as a hydrostatic head in millimetres (mm). This indicates the pressure of water needed to penetrate a fabric. Heavy or wind-driven fall has a higher pressure than light rain. Condition on a groundsheet increases the pressure on any sodden underneath. Fabric with a hydrostatic head of 1000 mm or less is best regarded as shower resistant, with 1500 mm being sometimes suitable for handle camping. Tents for year-round convenience generally have at least 2000 mm; expedition tents intended for extreme conditions are often rated at 3000 mm

Many tent manufacturers indicate capacity by such phrases as "3 berth" or "2 person". These numbers indicate how multiplied people the manufacturer thinks can be fit snugly into a tent with just sleeping bags. These numbers do not allow for any personal belongings such as luggage, inflatable mattresses, camp beds, cots, etc. nor do they allow for people who are of above Family Tents customary height. Checking the quoted sizes of sleeping areas reveals that several manufacturers consider that a width of 150 cm (5 feet) is enough for 3 people - snug is the operative word. Experience indicates that camping may be greater comfortable if the actual number of campers is 1 or even 2 less than the manufacturer's suggestion.