Area units are squares of length units, so the conversion factor is the length factor squared. One foot is 0.3048 m, so one square foot is 0.3048² = 0.09290304 m² — a factor people often get wrong by forgetting to square.
For land, the US uses acres (43,560 ft², historically the area one ox team could plough in a day) and most of the world uses hectares (a 100 m × 100 m square). A hectare is about 2.47 acres.
Floor plans in the US are quoted in square feet and elsewhere in square meters; a 1,000 ft² apartment is roughly 93 m².
Frequently asked questions
How many square feet are in a square meter?
About 10.764 ft².
How big is an acre?
Roughly 209 ft × 209 ft, or about three-quarters of an American football field without the end zones.