Question: what is 40 ft in square feet?
Answer: 1 acre = 43,560 square feet. To calculate the area of a room in square feet, measure the length and width of the room in feet, then multiply these figures together to give an area in ft². For example, a room measuring 12 ft x 15 ft would be described as having an area of 180 ft² (12 x 15 = 180).