Roof Calculator
Estimate concrete, steel and materials for an RCC roof.
About the Roof Calculator
The Roof Calculator gives you a clear, instant answer to a question that usually means digging through tables or guessing — enter your numbers and read the result straight away.
Reinforced cement concrete (RCC) is the skeleton of every Pakistani building, and its cost depends on the concrete volume and the steel reinforcement ratio. This Roof Calculator estimates the concrete, steel and total cost for slabs, beams, columns and foundations.
The calculation uses the volume of the structural member and standard steel ratios — typically 1–1.5% of concrete volume for slabs and 2–3% for columns and beams — to arrive at the tonnage of steel and bags of cement required.
Steel is quoted per ton in Pakistan and its price swings with the international market, while cement is per bag. This tool converts the structural quantities into both, letting you price the RCC portion of your build accurately.
Structural design should always be checked by a qualified engineer — this calculator gives you the budgeting numbers, not the design. Use it to sanity-check contractor estimates and quantity lists.
Come back to the Roof Calculator whenever your numbers change; because everything runs live in your browser, you can re-run it as many times as you need at no cost.
How to estimate RCC cost
- 1
Enter the dimensions of the slab, beam, column or foundation.
- 2
Adjust the steel ratio and current steel/cement prices if needed.
- 3
Read the concrete volume, steel tonnage and total cost, updated live.
Frequently Asked Questions
How is RCC quantity estimated?
Volume = length × width × height. For a 1:2:4 mix, each cft of concrete needs about 0.22 bags of cement, 0.44 cft sand and 0.88 cft crush. Steel is estimated at 1–2% of concrete volume by weight.
How much steel is used in a house?
A typical Pakistani house uses 3,000–5,000 kg of steel per 1,000 sq ft of covered area, depending on design. Slabs use less per cubic metre than columns and beams.
How is steel weight calculated?
Steel weight per metre is calculated as diameter² / 162 in kilograms. For example, a 12 mm bar weighs about 0.89 kg per metre. This calculator handles the conversion for you.