The calculation, without hidden assumptions
Calculate theoretical mass for solid plain round bar from first-principles circular geometry and material density. This owner is for round stock, rods and shaft material—not ribbed reinforcement schedules—and keeps theoretical, procurement and supplier-comparison values separate.
How to use this calculator
Enter the nominal solid-bar diameter.
Enter piece length and whole-piece quantity, choosing metric or imperial units.
Use 7,850 kg/m³ for carbon steel or enter documented density for another alloy.
Optionally add procurement allowance, rate/kg, target mass or supplier kg/m.
Review substituted working and any supplier variance before ordering or transport planning.
Where people use it
- •Estimate mild-steel round bar or shaft-stock mass.
- •Convert a cut list into batch weight and material cost.
- •Compare carbon steel with stainless, aluminum, brass or another documented density.
- •Reverse a payload or purchasing target into whole equal-length pieces.
- •Check supplier/table kg/m against nominal geometry without overwriting the theoretical result.
25 mm steel round bar, 6 m × 10 pieces
Area = π/4 × 25² = 490.874 mm². At 7,850 kg/m³, unit mass is about 3.853 kg/m. One 6 m piece is about 23.12 kg and 10 pieces are about 231.20 kg before allowance.
What the result does not assume
- •This owner models solid plain round stock; use the dedicated Rebar Weight Calculator for reinforcement-bar intent.
- •Results use nominal circular diameter and the density you enter.
- •Diameter tolerances, coatings and actual alloy chemistry can change delivered mass.
- •Allowance is an explicit procurement planning input, not a manufacturing or engineering standard.
- •Mass geometry does not establish strength, shaft capacity, lifting safety or code compliance.
Frequently asked questions
What is the round bar weight formula?+
For a solid round bar, area = πd²/4. Multiply that area by length and material density. With diameter in millimetres, kg/m = πd²/4 × 10⁻⁶ × density in kg/m³.
Why do steel charts use d²/162 or d²/162.2?+
That is a rounded shortcut obtained by substituting about 7,850 kg/m³ steel density into the circular-area formula. MAXScanner keeps density explicit so the same geometry works for other materials.
How much does a 25 mm steel round bar weigh?+
At 7,850 kg/m³, a 25 mm solid round bar is about 3.853 kg/m, so a 6 m piece is about 23.12 kg.
Can I calculate round bar weight in pounds per foot?+
Yes. Enter inches and feet if preferred; results include both kg/m and lb/ft plus total kilograms and pounds.
Why can supplier weight differ from the calculator?+
Nominal diameter, dimensional tolerance, coating and actual material density can differ. Enter supplier kg/m to see the percentage variance while preserving the theoretical result.
Is round bar the same as rebar?+
No. This calculator owns plain solid round stock and shaft/rod intent. Reinforcing bar has product-specific nominal sizes and ribbed profiles, so MAXScanner keeps rebar as a separate canonical workflow.
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.