5+ Floor Ratio Calculation. Floor area ratio (far) is a measure of the relationship between the total usable floor area of a building and the total area of the lot on which it stands. Learn how to calculate floor area ratio (far) for your project, including zoning impacts and different building types.

Floor area ratio (far) is a measurement, expressed as a decimal, that describes the total amount of usable floor space in a building compared to the size of the lot that the building is on. Calculation of floor area ratio. Learn how to calculate floor area ratio (far) for your project, including zoning impacts and different building types.





