Floor Area Ratio Calculator — FAR & Plot Coverage
Enter your plot area, building footprint and number of floors to get the Floor Area Ratio (FAR) and plot coverage — the two key metrics used in zoning regulations to control building density.
m²
m²
floors
Total floor area ÷ plot area — the key zoning density measure
- 1
Total floor area
200 × 5 = 1,000 m² - 2
Floor Area Ratio
1,000 ÷ 500 = 2
How does this calculator work?
FAR = Total Floor Area / Plot Area. A 5-storey building with a 200 m² footprint on a 500 m² lot has 1 000 m² total floor area, giving FAR 2.0 and 40% plot coverage. FAR is the main zoning density control — limits range from 0.3 in low-rise suburbs to 10+ in dense urban cores.
Formula
How this is calculated
Floor Area Ratio (FAR) — also called Floor Space Index (FSI) or Site Ratio — is the ratio of a building's total gross floor area to the area of the land it sits on. A FAR of 2.0 on a 500 m² plot means 1 000 m² of total floor area, whether achieved as two fully covering floors, five floors covering 40% of the plot, or any other combination that totals 1 000 m². FAR is the primary tool used by planners to control building density: low-rise suburban zones typically allow FAR 0.3–0.8; mid-density mixed-use zones 1.0–3.0; and high-density urban cores 4.0–15.0 or more.
Plot coverage (sometimes called the Building Coverage Ratio, BCR, or Ground Coverage Ratio, GCR) is a separate, complementary measure: the proportion of the plot occupied by the building footprint at ground level. It controls how much open space, light and air circulation are preserved around the building. A plot of 500 m² with a 200 m² footprint has 40% coverage and 60% open area.
This calculator assumes a uniform floor plate on every storey. In practice, buildings often have set-backs on upper floors, basements that count partially toward FAR, mechanical floors that may be exempt, or podiums with different coverage rules. Always verify with the applicable local planning regulations, as definitions and exemptions vary significantly by jurisdiction.
Frequently asked questions
FAR limits vary widely by zone and country. Suburban single-family zones often allow FAR 0.3–0.8; low-rise commercial zones 1.0–2.0; mid-rise mixed-use 2.0–5.0; and high-density urban cores can allow FAR 10–20 or higher for skyscrapers. Check your local zoning ordinance for the precise allowable FAR.
No. FAR (Total Floor Area ÷ Plot Area) measures overall density including all floors, while plot coverage (Footprint ÷ Plot Area) measures only how much of the ground is covered. A tall narrow building can have a high FAR with low plot coverage; a sprawling low building can have low FAR but high coverage.
It depends on jurisdiction. In many countries basements used for parking are fully or partially excluded from FAR calculations; habitable basement space (apartments, offices) is typically included. Service floors, mechanical rooms and rooftop plant areas are also treated differently by different codes. Check local definitions before designing a project.
Also known as
TG we-Calculate Editorial Team. (2026). Floor Area Ratio Calculator — FAR & Plot Coverage [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/floor-area-ratio-calculator
TG we-Calculate Editorial Team. "Floor Area Ratio Calculator — FAR & Plot Coverage." TG we-Calculate. 2026. https://we-calculate.com/calculator/floor-area-ratio-calculator.
TG we-Calculate Editorial Team, "Floor Area Ratio Calculator — FAR & Plot Coverage," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/floor-area-ratio-calculator
@misc{wecalculate_floor_area_ratio_calculator, title = {Floor Area Ratio Calculator — FAR & Plot Coverage}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/floor-area-ratio-calculator}}, year = {2026}, note = {TG we-Calculate} }
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