Free construction calculator · Metric and imperial
Rebar Weight Calculator
Estimate reinforcement weight from bar diameter, total length, quantity, and waste allowance in metric or imperial units.
Inputs
Enter measured dimensions
Formula and assumptions
Metric unit weight (kg/m) = diameter² / 162; total weight = unit weight × length × quantity
Use measured dimensions from the latest approved information. Check deductions, laps, allowances, material modules, supplier constraints, and rounding rules before ordering or certifying quantities.
The result is an estimate for planning and checking. It does not replace a coordinated quantity takeoff, temporary-works design, structural design, geotechnical assessment, or project-specific engineering review.
Questions
Why is rebar weight calculated with d²/162?
For metric reinforcing steel, d²/162 is a common approximation of kilograms per metre based on steel density and a circular cross-section.
Should laps and wastage be included?
Yes. Add lap lengths, hooks, couplers where relevant, cutting waste, and project-specific allowances before procurement.