Squared units
An area unit is a length unit squared, so its factor is the length factor squared. A foot is 0.3048 m, so a square foot is 0.3048 × 0.3048 = 0.09290304 m². That is why 1 m² is 10.76 square feet, not 3.28: the 3.28 feet in a metre count twice.
Land: acres and hectares
A hectare is 10,000 m², a square 100 m on each side, and is 2.47 acres. An acre is 4,046.86 m², and a square mile holds exactly 640 acres. A 105 by 68 m football pitch covers 0.71 hectares, or 1.76 acres.
Questions
How do I find the square feet of a room?
Multiply the length by the width in feet: a room 12 ft by 15 ft is 180 sq ft. Type 180 here with square feet chosen to get 16.72 m².
Can it turn a length into an area?
No. A length and an area measure different things. Multiply two lengths in the same unit first, then convert the result.