Why we built this
Construction maths in Pakistan runs on units no global calculator understands. A plot is sold in marla and kanal, a flat in gaj; cement comes in 50 kg bags, rebar is sized by the d²/162 rule, and concrete is batched by nominal mixes like 1:2:4. MistriCalc puts that everyday material and land math in one place — in the units and formulas Pakistani construction companies, builders and contractors actually trust — so you can scope a job, order materials, and sanity-check a quote without a spreadsheet on the site office desk.
How we calculate
Every tool uses standard trade formulas and published constants. The table below documents the core method and the key assumptions behind each calculator category, so you can see precisely what a result represents. The calculators run entirely in your browser in plain JavaScript — nothing you type is sent to a server or stored.
| Calculator | Core method | Standards & key assumptions |
|---|---|---|
| Land Area Converter | Convert every unit through a square-foot factor: ft² = value × from-factor; result = ft² ÷ to-factor. | Standard factors: gaj/sq yd = 9 ft², marla = 272.25 ft² ("shahjahani"), kanal = 20 marla = 5,445 ft², acre = 43,560 ft². Marla and kanal can vary slightly by area — always confirm the unit used locally against revenue records. |
| FAR / FSI Calculator | Permissible built-up = plot area × FAR (FSI); max footprint = plot × ground-coverage %; floors ≈ built-up ÷ footprint. | FAR and FSI are the same ratio under different names. Permissible FAR, coverage and setbacks are set by your local development authority / bye-laws — enter your sanctioned figure. |
| Construction Cost | Total = built-up area (sq ft) × rate per sq ft; split into material vs labour (≈ 60/40). | Basic / standard / premium rate presets are editable starting points only. Rates vary by city, year, spec and finish — always confirm against current local quotes. Cost shown in Pakistani Rupees (Rs). |
| Concrete Calculator | Dry volume = wet volume × 1.54; cement volume = dry × (cement part ÷ Σ parts); cement bags = cement volume ÷ 0.0347; sand & aggregate by their mix parts. | Nominal mix ratios (M5 1:5:10 … M15 1:2:4, M20 1:1.5:3, M25 1:1:2). 1 cement bag = 50 kg = 0.0347 m³ = 1.226 CFT. Densities ≈ 1,550 kg/m³ sand, 1,450 kg/m³ aggregate for tonnage. Design mixes (M25+) should be confirmed by a mix design. |
| Steel Weight | Weight per metre = d² ÷ 162 (d in mm); total = per-metre × length × quantity. Per foot ≈ d² ÷ 533. | Derived from steel density 7,850 kg/m³ (πd²/4 × 7850 ≈ d²/162.28). Applies to standard TMT/mild-steel round bars. |
| Brick Calculator | Bricks = wall volume ÷ (brick + mortar joint) volume; mortar volume = wall − brick volume; cement & sand from the mortar mix via the 1.33 dry factor. | Standard Pakistani brick 9×4.5×3 in; modular 190×90×90 mm (+10 mm joint) and traditional 230×110×70 mm also supported. Assumes ~10 mm mortar joints. Add wastage for breakage. |
| Plaster Calculator | Wet volume = area × thickness; dry volume = wet × 1.27; cement & sand split by the mix parts. | Typical thickness 12 mm (internal) / 15–20 mm (external); mixes 1:4 to 1:6. 1 bag = 50 kg = 0.0347 m³. |
| Tile Calculator | Tiles = area ÷ tile area × (1 + wastage %); adhesive ≈ 3–4 kg/m² ÷ 20 kg bag. | Wastage typically 5–10% (more for diagonal/patterned layouts). Traditional bedding uses cement + sand instead of adhesive. |
| Paint Calculator | Litres = (wall area − openings) × coats ÷ coverage. | Coverage ≈ 110 sq ft per litre per coat on a primed surface; varies by paint, surface and method. Cost shown in Pakistani Rupees (Rs). |
| RCC Slab Calculator | Concrete volume = L × W × thickness; cement/sand/aggregate at a default grade (as the concrete tool); steel ≈ 80 kg per m³ of slab (editable). | The 80 kg/m³ steel figure is a rule-of-thumb for ordering only. Actual reinforcement must come from a structural design by a qualified engineer. |
| AC Tonnage Calculator | Tonnage ≈ room area (sq ft) ÷ 600, adjusted for ceiling height, occupancy, sun exposure and top-floor; rounded to 0.8 / 1.0 / 1.5 / 2.0 T. | Rule-of-thumb sizing (1 ton ≈ 12,000 BTU). Hot-climate, west-facing and top-floor rooms need more; a proper heat-load survey is the accurate method. |
| Water Tank Calculator | Daily demand = occupants × per-capita litres/day → tank size; or capacity (litres) = L × W × H (m) × 1,000. | Default per-capita demand 135 L/day (standard residential design figure, editable). 1 m³ = 1,000 litres. |
Units & standards we use
- Cement bag: 50 kg = 0.0347 m³ = 1.226 CFT.
- Dry/wet factors: concrete 1.54, plaster 1.27, brick mortar 1.33.
- Steel: kg/m = d²/162 (and ≈ d²/533 kg/ft), from 7,850 kg/m³ density.
- Water demand: 135 L/person/day (standard residential design figure).
- Land: standard factors above, with a prominent "varies by region" note on every land result.
Sources & how we keep this accurate
Formulas and constants are drawn from widely used structural codes and standard trade practice: nominal concrete mixes and the 1.54 dry factor, conventions and the d²/162 rule for reinforcement steel, the 135 litre per-capita water demand figure, and standard brick sizes used in Pakistan. Land-unit factors follow the standard "shahjahani" system documented by revenue departments, with regional variations called out. Each calculator carries its own cited source and a review date, and we review the formulas and constants periodically. Spotted a number that looks off? Tell us on the contact page.
Methodology last reviewed 2026-06-14
What this is not
MistriCalc gives educational estimates to help you scope and order materials. All figures are estimates — confirm land area with local revenue records and consult a qualified engineer for structural design. It is not engineering, legal, code-compliance, or professional advice. Land-unit factors (marla, kanal and others) can vary by area, so always verify the unit used locally before buying, selling, or registering a plot.
Get in touch
Want a calculator we don't have yet, or spot a number that looks wrong? Reach us on the contact page.