Calculadora de Ferro/Aço (Peso de Vergalhão)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
kg = L × d² × 0,00617 (d em mm)
About this calculator
The Steel/Iron Rebar Weight Calculator determines the weight of steel bars based on diameter and length. It uses the formula kg = L × d² × 0.00617, where L is length in meters and d is diameter in millimeters. This formula is widely used in civil construction for material estimates.
The factor 0.00617 derives from steel density (7,850 kg/m³) and unit conversions. It simplifies calculations: for each meter of rebar, weight per meter is d² × 0.00617 kg/m. Then multiply by total length. This tool is useful for engineers, architects, and construction professionals needing quick budgets.
You can use this calculator when planning reinforced concrete structures like slabs, beams, and columns. It helps avoid waste or shortages. For example, a 12 mm bar 12 meters long weighs approximately 12 × 12² × 0.00617 ≈ 10.66 kg. Note that the result is theoretical; actual weight may vary slightly depending on steel grade.
Important precautions: ensure diameter is in millimeters and length in meters. The formula assumes common steel (CA-50, CA-60). For special or stainless steels, density may differ, altering weight. Also, the result does not include losses from cutting or splicing. Always round up in budgets for safety margin.
Frequently asked questions
What formula does the calculator use?
The formula is kg = L × d² × 0.00617, where L is length in meters and d is diameter in millimeters.
Does this calculator work for any type of steel?
It is ideal for common steels like CA-50 and CA-60. For stainless or special steels, density may vary, so weight may differ.
How do I convert weight to tons?
Simply divide the result in kg by 1000. For example, 500 kg equals 0.5 tons.
Does the result include cutting losses?
No. The calculation is theoretical based on total bar length. For budgets, add a 5% to 10% margin for losses.
Can I use the calculator for fiberglass rebar?
No. The formula is specific to steel. Fiberglass rebar has a different density and requires a different calculation.