MistriCalc → FAR / FSI Calculator
FAR / FSI Calculator
Work out the permissible built-up area, maximum footprint and likely number of floors for your plot from the sanctioned FAR/FSI and ground coverage.
Land & property explainer
Check the numbers first, then read how they work. Start with the calculator below — the example values are pre-filled with a typical Pakistani plot — then keep scrolling for the FAR vs FSI difference, a worked example and the questions builders ask most. Everything runs in your browser; nothing you type is stored.
Calculator
FAR (Floor Area Ratio) and FSI (Floor Space Index) are the same thing: the ratio of total permissible built-up floor area to your plot area. Your permissible built-up area = plot area × FAR. A separate rule, ground coverage, caps how much of the plot one floor may occupy, so your maximum footprint = plot area × coverage %. Dividing the allowance by the footprint gives a rough number of floors.
Key takeaways
- FAR = FSI — same ratio, just different names (FAR is sometimes a %).
- Permissible built-up = plot × FAR. 2,000 ft² × 1.5 = 3,000 ft².
- Max footprint = plot × coverage %. 2,000 ft² × 50% = 1,000 ft².
- Floors ≈ built-up ÷ footprint. 3,000 ÷ 1,000 = 3 floors.
- Always use the sanctioned FAR for your plot — it varies by zone.
FAR vs FSI — what's the difference?
Despite the different names, FAR and FSI are identical. Both express how much total floor area you may build relative to the size of the land. Some authorities use "FSI" and others use "FAR"; some write it as a percentage (FAR 150) and others as a decimal (FSI 1.5). They all describe the same allowance: total floor area ÷ plot area.
Ground coverage and FAR work together. FAR limits the total floor area you may stack across all storeys, while ground coverage limits the footprint on any single floor. You hit whichever cap comes first.
Worked example: a 2,000 ft² plot in a 1.5-FSI zone
Suppose you own a 2,000 sq ft residential plot (about 7.35 marla) where the authority allows an FSI of 1.5 and 50% ground coverage. Permissible built-up area is 2,000 × 1.5 = 3,000 sq ft. Maximum footprint is 2,000 × 0.50 = 1,000 sq ft per floor. Dividing, 3,000 ÷ 1,000 = 3 floors at full footprint. If you plan 2,700 sq ft of built-up, you are using 2,700 ÷ 3,000 = 90% of your allowance — within limits, with 300 sq ft to spare.
Typical FAR / FSI values
| Context | FAR / FSI | As % |
|---|---|---|
| Low-density residential | 1.0 | 100% |
| General residential plot | 1.5 | 150% |
| Plots on wider roads | 2.0 | 200% |
| High-density / TOD zones | 2.5 – 4.0 | 250 – 400% |
| Commercial / mixed-use | varies widely | — |
Indicative only — every city's development authority sets its own FAR by zone, plot size and road width.
Plan the rest of your build
Once you know your buildable area, estimate the cost with the construction cost calculator, the slab with the RCC slab calculator, and convert plot units with the land area converter.
Frequently asked questions
What is the difference between FAR and FSI?
None — FAR (Floor Area Ratio) and FSI (Floor Space Index) are two names for the same ratio of built-up area to plot area. FAR is sometimes written as a percentage (150%) and FSI as a decimal (1.5), but they mean the same thing.
How do I calculate permissible built-up area from FAR?
Multiply plot area by the FAR/FSI value. A 2,000 ft² plot with FSI 1.5 gives 3,000 ft² of permissible built-up area across all floors.
What is ground coverage and how is it different from FAR?
Ground coverage caps your footprint on a single floor (plot × coverage %); FAR caps total floor area across all floors. With 50% coverage on 2,000 ft², the footprint is limited to 1,000 ft².
How many floors can I build?
As a rough guide, permissible built-up ÷ maximum footprint. 3,000 ÷ 1,000 ≈ 3 floors. Real floors also depend on height limits, setbacks and bye-laws.
Does built-up area include balconies and stairs?
It depends on local bye-laws. Staircases, lift cores, balconies and parking basements often get partial or full FAR exemptions. Confirm what counts toward FAR with your municipal authority.
Is FAR the same everywhere in Pakistan?
No. Each development authority sets FAR by zone, plot size and road width. Residential values commonly range from about 1.0 to 2.5. Always check the sanctioned FAR for your plot.
FAR/FSI is defined as permissible floor area ÷ plot area and ground coverage as footprint ÷ plot area — both standard town-planning definitions used by Pakistani building control authorities (such as LDA, CDA and SBCA). Actual sanctioned values, FAR-free allowances and floor limits are set in each city's building bye-laws.
Last reviewed 2026-06-14