FSI / FAR Room Count Calculator
Estimate how many hotel rooms your plot can hold from FSI, ground coverage, floor limit, efficiency and room size, floor by floor.
How to use the free FSI / FAR Room Count Calculator
- Enter your figures in the fields above – use real numbers from your PMS, channel manager or accounts.
- Tap the button to see the result instantly. Change any value to compare scenarios.
- Copy, print or save the result and use it in your daily or monthly review.
This FSI / FAR Room Count Calculator runs fully in your browser on mobile or desktop – no sign-up and nothing is uploaded. Free FSI / FAR room count calculator for hotels. Enter plot area, FSI, ground coverage, floors and room size to estimate built-up area and rooms.
How FSI decides your room count
Floor Space Index (FSI), also called Floor Area Ratio (FAR), is the total built-up area you may construct divided by the plot area. An FSI of 2 on a 20,000 sq ft plot allows about 40,000 sq ft of built-up area. Two other rules usually cap you as well: ground coverage, which limits the footprint of each floor, and a height or floor limit for the zone. The built-up area you can really use is the lower of the FSI limit and footprint multiplied by floors.
Rooms ≈ Usable built-up × Efficiency % ÷ Room size
Why efficiency matters so much
Not every square foot becomes a saleable room. Lobby, reception, restaurant, kitchen, corridors, staircases, lift shafts, stores, staff areas and plant rooms all take space. In a rooms-led budget or midscale hotel, rooms often take about 55–60% of built-up area. A full-service hotel with banquets and a large restaurant may be well below 50%. Change the efficiency field to test both cases.
- Room size: use carpet area including the bathroom. Bigger rooms mean fewer keys on the same plot.
- Typical floor: the tool fills each floor up to the footprint limit and shows a part floor if FSI runs out.
- Unused FSI: if floors or coverage bind first, the tool tells you how much FSI is left on the table.
Example
A 20,000 sq ft plot with FSI 2, 40% ground coverage and six floors gives 40,000 sq ft built-up across five floors of 8,000 sq ft. At 55% efficiency and 280 sq ft rooms, each floor holds 15 rooms, so about 75 rooms in total.
Before you buy land or brief an architect
FSI, coverage, setbacks, parking, fire norms and height limits differ by state, city, zone and road width, and premium FSI or TDR may be available at extra cost. Treat this as a first screening number only and confirm everything with a licensed architect and the local authority. Next, estimate the budget with the construction cost calculator and test viability using the hotel feasibility calculator.
Frequently asked questions
What is FSI or FAR for a hotel?
FSI or FAR is the ratio of total built-up area to plot area. An FSI of 2 on a 10,000 sq ft plot allows about 20,000 sq ft of construction. Values differ by city, zone and road width, so check local rules.
How many rooms can I build on my plot?
Multiply usable built-up area by the share that goes to rooms, often 55 to 60 percent, and divide by the room size including bathroom. This calculator does this floor by floor.
Does FSI include basements and staircases?
It depends on your local bye-laws. Many cities exclude basements used for parking or services and some exempt lift wells or staircases. Ask your architect to confirm what counts.
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