Transparent formulas

Grey structure calculator methodology

A complete audit trail for area conversion, cost factors, material ratios, estimate range and assumptions.

The calculator is a deterministic planning model. Given the same inputs, it returns the same result. It does not fetch live market prices and does not claim that its built-in assumptions are official rates.

Rates/assumptions last reviewed: 9 August 2026. Built-in rates and factors are illustrative defaults, not evidence of current prices. A dated local all-in rate is recommended.

1. Convert the input to total covered area

Square feet need no conversion. For marla, the selected 225 sq ft, 272.25 sq ft or custom factor is used. One kanal is treated as 20 of the selected marla convention.

Per-floor mode: total covered area = entered area × number of storeys
Plot mode: total covered area = plot area × coverage % × number of storeys

Coverage is a planning input, not an approval check. Local building regulations and approved drawings determine allowable covered area.

2. Calculate the built-in effective rate

Quality base rates
QualityBase PKR/sq ft
Economy2,800
Standard3,350
Premium3,950
Illustrative built-in city factors
City or groupFactor
Islamabad1.09
Karachi1.06
Rawalpindi1.04
Abbottabad1.02
Sialkot1.01
Lahore1.00
Hyderabad0.99
Gujranwala, Sheikhupura, Gujrat0.98
Faisalabad, Mingora / Swat0.97
Multan, Sargodha, Mardan, Kasur, Nowshera0.96
Peshawar, Bahawalpur, Sahiwal, Okara0.95
Quetta, Jhang, Nawabshah, Chiniot0.94
Sukkur, Rahim Yar Khan, Mirpur Khas0.93
Larkana, Dera Ghazi Khan0.92
Additional Pakistan locations added with a neutral fallback factor
RegionLocations availableFactor
Gilgit-BaltistanGilgit, Skardu / Baltistan, Hunza / Aliabad, Chilas / Diamer, Khaplu / Ghanche1.00
Azad Jammu and KashmirMuzaffarabad, Mirpur, Kotli1.00
PunjabJhelum, Chakwal, Attock, Taxila / Wah, Murree, Bahawalnagar, Vehari, Khanewal, Muzaffargarh, Mandi Bahauddin, Narowal, Hafizabad, Pakpattan, Toba Tek Singh1.00
Khyber PakhtunkhwaMansehra, Haripur, Kohat, Bannu, Dera Ismail Khan, Charsadda, Swabi1.00
SindhJacobabad, Khairpur, Shikarpur, Dadu, Badin, Thatta1.00
BalochistanGwadar, Turbat, Khuzdar, Chaman, Zhob1.00
Any other Pakistan locationOther Pakistan location1.00

The neutral 1.00 factor is a transparent fallback, not a claim that these markets have Lahore pricing. For Gilgit, Baltistan and every other added location, enter a current local all-in rate when one is available.

Storey cost and material factors
StoreysCostCementSteelMasonry
Single1.001.001.001.00
Double1.061.041.071.03
Triple1.121.081.141.06

Effective rate = quality base × city factor × storey cost factor
Total estimate = total covered area × effective rate

When a user supplies a custom all-in rate, that rate becomes the effective rate directly. City and storey cost factors are not added because the local rate may already reflect them.

Pakistan map and construction plans illustrating location-based cost variation
City and storey multipliers are transparent planning assumptions, not official market quotations.

3. Calculate the planning range

The lower result is 94% of the estimate and the upper result is 106%. This illustrative ±6% range is not a statistical confidence interval and may be much narrower than real project uncertainty.

4. Estimate major materials

Base material ratios per covered square foot
MaterialRatioStorey factor
Cement0.43 bagsCement factor
Steel / saria4.20 kgSteel factor
Bricks34 bricksMasonry factor
Sand1.75 cftMasonry factor
Crush1.45 cftMasonry factor

Material quantity = total covered area × base ratio × matching storey factor

Where the crush allowance needs a separate bulk-material check, a stone volume calculator can help compare the planning ratio with a stated volume estimate.

Cement bags, steel reinforcement, bricks, sand and aggregate in a grey-structure material breakdown
Per-square-foot ratios are early planning placeholders until project drawings and take-offs provide better quantities.

Worked calculation

For 3,000 sq ft total covered area, standard quality, Lahore and two storeys:

  • Effective rate = 3,350 × 1.00 × 1.06 = PKR 3,551/sq ft
  • Total = 3,000 × 3,551 = PKR 10,653,000
  • Cement = 3,000 × 0.43 × 1.04 = 1,342 bags after rounding
  • Steel = 3,000 × 4.20 × 1.07 = 13,482 kg
  • Bricks = 3,000 × 34 × 1.03 = 105,060

What the model does not know

It does not read soil reports, structural drawings, architectural complexity, contract exclusions, taxes, site access, boundary-wall scope, basement work, utility connections, market quotations or contractor overhead. These need professional and local review.

Civil engineer checking an unfinished concrete frame and brick infill on site
Project-specific drawings, ground conditions, accepted work and professional review sit outside a deterministic calculator.

Evidence hierarchy used on this site

Not every number deserves the same confidence. The calculator therefore distinguishes between mathematical conversions, published technical context and editable planning assumptions.

  1. Project documents: approved drawings, specifications, soil recommendations and written contract scope should control a real project.
  2. Official publications: PEC codes, local authority regulations, PSQCA standards catalogues and PBS price tables provide context but do not replace project documents.
  3. Measured site evidence: actual dimensions, delivery records, test reports and accepted quantities help reconcile a running job.
  4. Calculator assumptions: base rates, city factors and per-square-foot material ratios are transparent placeholders until replaced or checked locally.

The built-in rate table is intentionally not labelled “official.” PBS publishes item prices, not a universal all-in grey-structure rate, and local authority rules do not establish one national covered-area definition for every project.

Terminology used

Covered area
Floor area counted as constructed under the project’s measurement method.
Saria
Common Pakistani term for steel reinforcement bars used in RCC work.
RCC
Reinforced cement concrete containing designed steel reinforcement.
Crush
Crushed stone aggregate used in concrete and related works.

Methodology FAQ

Are the built-in rates current market prices?

No. They are illustrative defaults for demonstrating the model. Use a dated local all-in rate for a current project estimate.

Why are multi-storey material factors applied to total covered area?

The model first computes total covered area across floors, then applies illustrative material multipliers intended to represent structural complexity.

Can I audit a result manually?

Yes. This page publishes the base rates, factors, material ratios and formulas needed to reproduce the result with a calculator or spreadsheet.

Sources and verification

  1. Pakistan Bureau of Statistics — Price StatisticsMonthly urban and rural construction-item price tables and national price-index publications.
  2. Pakistan Engineering Council — Building Code of Pakistan 2021National building-code context for safety, administration, structural work and the authority having jurisdiction.
  3. Pakistan Engineering Council — Building codes and standardsPEC index of the Building Code of Pakistan and related national code publications.
  4. Pakistan Engineering Council — Bidding Documents ImplementationOfficial context for project-specific tender data, schedules, specifications, drawings and bills of quantities.
  5. Capital Development Authority — Laws and regulationsExample of local building-control rules; the authority and limits differ by city, society and project.

Sources establish the technical context. Calculator planning assumptions remain separately labelled and should be checked for the specific project.

Return to the grey structure calculator or use the material calculator directory.