Methodology
How we calculate
Every number we use, where it comes from, and what we do not cover.
Where the thumb rules come from
The material quantities we use are standard rules followed across the Indian construction industry. They come from IS codes and from what site engineers actually use.
| Material | Per sq ft | Why |
|---|---|---|
| Cement | 0.40 bags | Normal RCC frame house |
| Steel | 4.00 kg | Normal RCC frame house |
| Sand | 1.80 cft | Concrete, mortar and plaster together |
| Aggregate | 1.35 cft | Concrete work |
| Bricks | 8.00 nos | Standard 190x90x90 mm brick |
| Paint | 0.18 litre | Two coats on a smooth wall |
Formulas we use
| Calculation | Formula |
|---|---|
| Steel weight | d x d / 162 kg per metre |
| Concrete dry volume | Wet volume x 1.54 |
| Cement bag volume | 1 bag = 50 kg = 1.226 cft = 0.0347 cum |
| EMI | P x r x (1+r)^n / ((1+r)^n - 1) |
| Buildable area | Plot area x FAR |
About the 162 in the steel formula
The mathematically exact figure is 162.28. We use 162 because that is what every steel chart, every dealer and every site engineer in India uses. If we used 162.28, our answer would not match the chart your supplier hands you, and you would rightly wonder which one is wrong.
The difference is tiny. On a 20 mm bar it is 2.470 kg per metre against 2.4649. Matching the industry is more useful than being decimal-perfect.
Where rates come from
Material rates and per sq ft rates are researched market figures held in our database, not fixed in the code. They are reviewed periodically and every page shows when.
Rates last reviewed August 2026.
City rates use a multiplier on a base rate. Metro cities are about 1.20, tier-1 cities 1.00, tier-2 around 0.90 and tier-3 around 0.85. Most of that difference is labour.
Cost split we use
| Head | Share |
|---|---|
| Labour | 24% |
| Cement | 15% |
| Steel | 15% |
| Sand and aggregate | 13% |
| Bricks | 9% |
| Doors and windows | 9% |
| Flooring and tiles | 9% |
| Electrical | 7% |
| Plumbing and sanitary | 6% |
| Paint and finishing | 5% |
What our calculators do not cover
- Deep or special foundations. Bad soil, hill slopes or high water table can add a lot.
- Boundary wall, gate, borewell, water tank. These are separate and often add 15 to 20%.
- Approvals and sanction fees. These vary by city and plot size.
- Site levelling and soil filling. Sometimes the biggest surprise on a project.
- Interior work. Furniture, modular kitchen and wardrobes are a separate budget.
- Architect and engineer fees. Usually 2 to 5% of the project.
- Lifts, solar, home automation. Add these separately.
What we are not
We are not engineers, architects or contractors. We do not give structural advice. These are planning tools that help you check whether a quotation is reasonable and whether your budget is realistic.
For anything you will actually build, get a proper structural design from a licensed engineer and a priced bill of quantities. Do not build from a website calculator.
Where to check these yourself
We would rather you verified our numbers than trusted them. These are the official sources behind the constants above.
| What | Source |
|---|---|
| Concrete mix ratios, steel grades, code requirements | Bureau of Indian Standards ā IS 456 (plain & reinforced concrete), IS 383 (aggregates), IS 1786 (TMT bars) |
| Labour rates and item rates used by government works | CPWD ā Delhi Schedule of Rates, revised periodically |
| Building bye-laws, setbacks, occupancy rules | National Building Code of India, plus your own municipal body |
| FAR / FSI and ground coverage for your plot | Your local development authority. These change by zone and plot size, and ours are indicative only. |
| Home loan rates and eligibility | RBI for policy rates; your own bank's sanction letter for the actual figure |
For steel weight we use dĀ²/162 because that is what every dealer chart in
India prints. The exact figure is 162.28 ā the difference is under 0.2% and matching the
chart your supplier hands you is more useful than being decimal-perfect.
If you find a mistake
Rates change and we do not always catch it. If a figure here is wrong for your area, please write to us. Local rate corrections are the most useful thing anyone sends us, because we cannot research every market ourselves.