Floor Area Ratio (FAR) Calculator
Fill in the values and the answer updates as you type.
How the Floor Area Ratio (FAR) Calculator works
FAR = total floor area of all floors ÷ lot area. Building coverage = footprint ÷ lot area × 100. Remaining buildable area = lot area × maximum FAR − total floor area. Zoning codes define what counts toward floor area (basements, balconies, and parking are treated differently), so confirm the exact rules with your local planning office. Example: A 500 m² lot with a 240 m² footprint and 2 floors has 480 m² of floor area, an FAR of 0.96, and coverage of 48 percent. Under a 1.2 FAR limit, 120 m² of floor area remains.
Inputs and results
The Floor Area Ratio (FAR) Calculator takes 5 inputs and gives 5 results.
What you enter
- Lot area (m²) — starts at 500.
- Building footprint (m²) — starts at 240.
- Number of floors — starts at 2.
- Maximum FAR allowed — starts at 1.2.
- Maximum building coverage (%) — starts at 60.
What you get
- Floor area ratio (FAR)
- Building coverage
- Total floor area
- Remaining buildable floor area
- Zoning check
Example: Floor Area Ratio (FAR) Calculator with the starting values
With lot area 500 m², building footprint 240 m², number of floors 2, maximum far allowed 1.2 and maximum building coverage 60 %, the calculator returns:
| Floor area ratio (FAR) | 0.96 |
|---|---|
| Building coverage | 48% |
| Total floor area | 480 |
| Remaining buildable floor area | 120 |
| Zoning check | Within both limits |
Change any value above and the results update straight away.
Floor Area Ratio (FAR) Calculator FAQ
How do I use the Floor Area Ratio (FAR) Calculator?
Enter lot area, building footprint, number of floors and maximum far allowed in the fields, then read floor area ratio (far), building coverage, total floor area and remaining buildable floor area in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Floor Area Ratio (FAR) Calculator calculate?
FAR, building coverage, and remaining buildable area under zoning limits. It returns floor area ratio (far), building coverage, total floor area and remaining buildable floor area from the 5 values you provide.
What values does the Floor Area Ratio (FAR) Calculator start with?
It opens with lot area 500 m², building footprint 240 m², number of floors 2 and maximum far allowed 1.2 so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Floor Area Ratio (FAR) Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Floor Area Ratio (FAR) Calculator for financial decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm financial decisions with a qualified professional. See the Disclaimer for more.