QUICK ANSWER
Plan on about 4 kg of reinforcement steel per sq ft of built-up area for G+1 to G+3 houses, so 1,000 sq ft needs about 4,000 kg. A ground-floor-only house uses about 3.4 kg per sq ft, G+4 about 4.32 and G+5 about 4.48. Check delivered bars by weight: kg per metre is d² ÷ 162.
The planning rule is about 4 kg of reinforcement per sq ft of built-up area. See how it changes with floors, how it splits between footings, columns, beams and slabs, and how to check a delivery by weight.
The thumb rule
For G+1 to G+3 houses, NirmanShastra's StructurePro starts from 4 kg of reinforcement steel per sq ft of built-up area. Built-up area is the total across all floors. A 1,000 sq ft house needs about 4,000 kg, and a 1,500 sq ft house about 6,000 kg.
How it changes with floors
The thumb rule is set for G+1 to G+3. Outside that range a factor applies. Per 1,000 sq ft of built-up area:
| Floors | Factor | Steel per sq ft | Steel for 1,000 sq ft |
|---|
| Ground floor only | 0.85 | 3.4 kg | 3,400 kg |
| G+1 to G+3 | 1.00 | 4 kg | 4,000 kg |
| G+4 | 1.08 | 4.32 kg | 4,320 kg |
| G+5 | 1.12 | 4.48 kg | 4,480 kg |
Binding wire is estimated at 12 kg per tonne of steel, so about 48 kg for 4,000 kg of reinforcement.
How it splits across members
Reinforcement is also planned as a percentage of each member's concrete volume. Multiply the percentage by the density of steel, 7,850 kg/m³, to get kilograms per cubic metre of concrete.
| Member | Steel as % of concrete | Steel per m³ of concrete |
|---|
| Footing | 0.5% | 39.25 kg |
| Column | 2.5% | 196.25 kg |
| Beam | 1.5% | 117.75 kg |
| Slab | 1.0% | 78.5 kg |
Weight of a bar per metre
Steel bars are billed by weight, and the weight per metre of a round bar is d² ÷ 162 kg, with d in millimetres.
| Diameter | Weight per metre | Weight of a 6 m bar |
|---|
| 8 mm | 0.395 kg | 2.37 kg |
| 10 mm | 0.617 kg | 3.70 kg |
| 12 mm | 0.889 kg | 5.33 kg |
| 16 mm | 1.580 kg | 9.48 kg |
| 20 mm | 2.469 kg | 14.81 kg |
Published weight tables round these to two or three decimals, so a difference in the third decimal place is not a red flag. A large gap is. Weigh before you accept.
Checking what was delivered
Weigh a handful of bars and divide the weight by the number of bars and their measured length. If five 12 mm bars of 6 m should weigh about 26.7 kg and weigh 22 kg, the delivery is about 17% light. The full site procedure is in how to catch steel theft on construction sites.
From weight to a cutting list
For a bar bending schedule, the Bar Bending Schedule Calculator gives cutting length and weight for 13 bar shapes using the IS 2502 bend and hook rules. For the rest of the structure, see cement, sand and aggregate for a 1,000 sq ft house. Terms such as TMT, Fe 500D and cover are in the glossary.
Frequently asked questions
How much steel does a 1,000 sq ft house need?
About 4,000 kg for a G+1 to G+3 house, from the thumb rule of 4 kg per sq ft of built-up area. A ground-floor-only house needs about 3,400 kg, G+4 about 4,320 kg and G+5 about 4,480 kg.
How much steel per sq ft for a 1,500 sq ft house?
About 6,000 kg of TMT steel at 4 kg per sq ft for G+1 to G+3.
What does a bar weigh per metre?
Weight in kg per metre is d² ÷ 162, with d in mm: 8 mm is 0.395, 10 mm 0.617, 12 mm 0.889, 16 mm 1.580 and 20 mm 2.469. Published tables round these to two or three decimals.
How much binding wire does the steel need?
About 12 kg of binding wire per tonne of steel, so roughly 48 kg for 4,000 kg of reinforcement.
How is steel split between footings, columns, beams and slabs?
As planning percentages of the concrete volume: footings 0.5%, columns 2.5%, beams 1.5% and slabs 1.0%. At 7,850 kg/m³ that is 39.25, 196.25, 117.75 and 78.5 kg of steel per cubic metre of concrete.
How do I check a steel delivery?
Weigh a sample of bars, divide by the number of bars and their measured length, and compare with the weight per metre. A 6 m, 12 mm bar should weigh about 5.3 kg.
