Steel Calculator
Thumb-rule steel (reinforcement) requirement for an RCC framed building, from built-up area and number of floors.
No login required · Early-budgeting estimate only
Thumb-rule estimate for early budgeting only — not a structural design. The actual quantity, bar diameters and bar bending schedule must come from a structural engineer based on spans, loads and seismic zone.
How this is calculated
Total built-up area (area per floor × number of floors) is multiplied by a kg-per-square-foot thumb rule that rises with floor count — lower-floor columns and footings in a taller building carry more cumulative load, so they need proportionally more reinforcement.
Steel (kg) = Total built-up area × kg/sqft rate
The bar count shown converts the total weight into an equivalent number of standard 12mm, 12-metre TMT bars, using the standard unit weight formula for reinforcement steel (d²/162 kg per metre, where d is the bar diameter in mm) — useful for a rough site-material count, not a cutting list.
Common questions
What is the thumb rule for steel quantity in construction?
A commonly used planning thumb rule is 3.5 to 5.5 kg of steel per square foot of built-up area for an RCC framed residential building, increasing with the number of floors.
Is a thumb rule accurate enough to buy steel?
No — it is only accurate enough for early budgeting. The actual quantity and bar diameters come from a structural engineer's design and bar bending schedule (BBS).
Why does steel requirement increase with more floors?
Columns and footings on the lower floors of a multi-storey building carry the cumulative load of everything above them, so they need proportionally more reinforcement than a single-storey structure of the same footprint.
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