A term commonly used to indicate the allowable square footage of a building according to zoning requirements. The ratio is between the total floor area of the building and the lot or plot on which it is built. Example: a 50,000 square foot lot may have a maximum of 100,000 square feet of floor area. A ten story building, each story having 10,000 square feet of floor space, would be allowed. The floor area ratio would be two to one, expressed simply as 2.