The calculation, without hidden assumptions
Calculate theoretical flat-bar mass from explicit rectangular cross-section geometry. MAXScanner keeps net material separate from procurement allowance, supports metric and imperial dimensions, and lets you compare supplier kg/m without replacing the theoretical result.
How to use this calculator
Enter nominal flat-bar width and thickness.
Enter cut length and whole-piece quantity, then choose metric or imperial units.
Use 7,850 kg/m³ for carbon steel or enter the documented density for your material.
Optionally add procurement allowance, rate/kg, target mass or supplier kg/m.
Review the substituted working and supplier variance before ordering.
Where people use it
- •Estimate MS or steel flat weight per metre and per foot.
- •Price fabrication takeoffs from cut length and quantity.
- •Add an explicit cutting/drop allowance without hiding it in geometry.
- •Reverse a payload or order target into whole cut pieces.
- •Compare theoretical mass with a supplier or measured kg/m value.
50 × 5 mm steel flat, 6 m × 10 pieces
Area is 50 × 5 = 250 mm². At 7,850 kg/m³, unit mass is 1.9625 kg/m. One 6 m piece is 11.775 kg and 10 pieces are 117.75 kg before any entered allowance.
What the result does not assume
- •The result is theoretical mass from nominal rectangular dimensions.
- •Rolled tolerances and edge shape can make delivered kg/m differ from geometry.
- •Density varies by alloy and grade; use documented material data when mass is critical.
- •Allowance is a procurement planning input, not a fabrication or structural standard.
- •This tool does not determine structural capacity, bending strength, lifting safety or code compliance.
Frequently asked questions
What is the flat bar weight formula?+
Multiply width by thickness for cross-sectional area, multiply by length for volume, then multiply by material density. With width and thickness in millimetres, kg/m = width × thickness × density × 10⁻⁶.
How much does a 50 × 5 mm steel flat weigh?+
Using 7,850 kg/m³, a 50 × 5 mm flat weighs 1.9625 kg/m, so a 6 m piece is about 11.775 kg.
Can I calculate flat bar weight in pounds per foot?+
Yes. Enter inches/feet if preferred; the result reports both kg/m and lb/ft plus total kg and lb.
Does the allowance change the theoretical kg/m?+
No. The calculator preserves theoretical geometry and applies the entered allowance only to procurement/order mass.
Why is supplier weight different?+
Nominal dimensions, rolling tolerances, edge profile, coating and actual alloy density can differ. Enter supplier kg/m to see the variance without overwriting the theoretical calculation.
Can this calculator verify structural capacity?+
No. Weight geometry does not establish strength, deflection, connections, buckling, grade compliance or safe working load.
Semantic next steps
Continue the calculation
These links move to a different input, formula or project stage rather than a keyword variation of this page.
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Keep the result connected to the real job
MAXScanner keeps the formula and assumptions beside the result so you can verify the number before using it in a drawing, estimate, specification, worksheet or document. Where a supplier, manufacturer, drawing or applicable standard owns a requirement, that source remains authoritative.