Calculate the weight of reinforcement steel bars using the standard D²L/162 formula. Add as many bar sizes as your project needs and get a combined total.
The standard formula is Weight (kg/m) = D² ÷ 162, where D is the bar diameter in millimetres. Multiply by the bar length and quantity for the total.
A 12mm bar weighs 12² ÷ 162 ≈ 0.888 kg per metre.
It's derived from steel's density (7850 kg/m³) and the cross-sectional area formula for a round bar, simplified into a constant for quick site calculations.