EngineerHub.orgHow to use this calculator
Select the nominal bar diameter, enter the bar count and cut length, then include an allowance for laps and offcuts.
Inputs
Results
Background
Engineering basis, equations, assumptions, interpretation and practical limitations for this calculator.
The common metric approximation is mass per metre = d² ÷ 162, where d is in millimetres.
Schedules should use the actual bar bending schedule. Hooks, bends, couplers, laps, chairs and wastage are not automatically measured.
Frequently Asked Questions
Practical questions about assumptions, inputs, interpretation and limitations.
Bending does not change mass per unit length, but the cut length must include bends, hooks, anchorage and other detailing dimensions.
No. It is a widely used practical approximation for metric reinforcement mass per metre based on nominal diameter and steel density. Manufacturer and standard tolerances still apply.
Yes. Quantity take-offs should include the actual bar lengths shown on approved drawings, including laps, hooks, anchorage, bends and any specified wastage.
For common US bar sizes #3 through #8, the bar number corresponds approximately to nominal diameter in eighths of an inch. Larger sizes follow standard nominal dimensions rather than a simple arithmetic rule.
No. The calculator estimates weight from selected size, length and quantity. Fabrication and procurement should use the approved bar bending schedule or structural drawings.