TMT Steel Calculator — Weight of Steel Bars
Calculate the weight of TMT reinforcement bars using the standard D² ÷ 162 formula, so you can order steel by weight instead of guessing.
Inputs
- Bar diameter (mm)
- Length of each bar (metres)
- Number of bars (bars)
How this calculation works
- Weight per metre (kg) = diameter² ÷ 162, with diameter in millimetres
- Total weight = weight per metre × bar length × number of bars
Example: A 12 mm bar weighs 144 ÷ 162 = 0.889 kg per metre. Fifty bars of 12 m each weigh 0.889 × 12 × 50 ≈ 533 kg.
Frequently asked questions
Where does the 162 in the steel formula come from?
It comes from the density of steel: weight = (π/4 × D² × 1000 × 7850) ÷ 1,000,000, which simplifies to D² ÷ 162 kilograms per metre.
How much steel does a house need per square foot?
Residential RCC construction in India typically uses 3 to 4 kg of steel per square foot of built-up area. Your structural drawing gives the exact bar bending schedule.