Steel Weight Calculator
Select a steel grade and stock shape, then enter the nominal dimensions, length, and quantity. The calculator returns theoretical weight for plate, pipe, round bar, square bar, or flat bar.
Planning a purchase? See what to include in your enquiry
Use this checklist when asking a supplier for a quote. Mark anything you are unsure about for confirmation.
- Material
- Grade and any specified material standard.
- Dimensions
- Plate, pipe or bar; dimensions and units.
- Quantity
- Number of pieces, length per piece or required weight.
- Tolerances
- Permitted dimensional variation, if specified.
- Finish and processing
- Surface finish, delivery condition and cutting requirements.
- Delivery
- Destination and preferred arrival date.
Add any inspection-document or packaging requirements. Theoretical weight is for planning; confirm the billing basis with the supplier.
Formula
Theoretical mass = section area × length × nominal steel density × quantity.
Solid rectangular section area = width × thickness; solid round section area = π × diameter² / 4.
Round pipe section area = π × (outside diameter² − inside diameter²) / 4, where inside diameter = outside diameter − 2 × wall thickness.
Weight per piece and total theoretical weight use the same unrounded mass; only the displayed value is rounded.
Common examples
Load a calculated example, then adjust its dimensions or quantity.
| Example | Inputs | Calculated answer | Load example |
|---|---|---|---|
| US plate quote checkA36 plate, 0.5 × 48 × 96 inA US plate quote can be checked from nominal dimensions and quantity, but the calculation does not confirm stock availability or mill tolerance. | Material or alloy: Steel ASTM A36; Shape: Plate or sheet; Thickness: 0.5 in; Width or side: 48 in; Length: 8 ft; Quantity: 2 | Total theoretical weight588.990409 kg | |
| Metric project takeoffCarbon steel plate, 12 × 1500 × 6000 mmFor a metric takeoff, calculate the full plate order and confirm grade, tolerance class, and cut length with the service center. | Material or alloy: Carbon steel; Shape: Plate or sheet; Thickness: 12 mm; Width or side: 1500 mm; Length: 6 m; Quantity: 6 | Total theoretical weight5,054.4 kg | |
| Machining stock order1018 round bar, 2 in × 12 ftMachining stock should include saw kerf, facing, and holding allowance in the ordered length before its theoretical weight is calculated. | Material or alloy: Steel AISI 1018; Shape: Round bar; Diameter: 2 in; Length: 12 ft; Quantity: 8 | Total theoretical weight466.743452 kg | |
| Production blank planningCarbon steel round bar, 60 mm × 6 mFull-length bar mass helps plan handling and yield; choose the required grade separately rather than inferring it from the geometry. | Material or alloy: Carbon steel; Shape: Round bar; Diameter: 60 mm; Length: 6 m; Quantity: 5 | Total theoretical weight661.619413 kg | |
| Pipe bundle estimateA53 Schedule 40 pipe from actual dimensionsCatalog outside diameter and wall thickness define the section; multiply the result by the actual number and length of pieces. | Material or alloy: Steel ASTM A53; Shape: Round pipe; Outside diameter: 4.5 in; Wall thickness: 0.237 in; Length: 21 ft; Quantity: 12 | Total theoretical weight1,234.713353 kg | |
| Metric piping estimateCarbon steel pipe, 88.9 × 5.49 mmActual metric geometry gives the metal-only pipe weight, while coating, end finish, and couplings may need separate shipment allowances. | Material or alloy: Carbon steel; Shape: Round pipe; Outside diameter: 88.9 mm; Wall thickness: 5.49 mm; Length: 6 m; Quantity: 20 | Total theoretical weight1,346.530476 kg | |
| Fabrication stock listSteel square bar, 1.25 in × 12 ftSquare-bar planning uses the solid stock dimensions and count, without adding welds, holes, or other finished-part features. | Material or alloy: Carbon steel; Shape: Square bar; Width or side: 1.25 in; Length: 12 ft; Quantity: 15 | Total theoretical weight431.38946 kg | |
| Workshop cut listSteel square bar, 40 mm × 6 mWorkshop teams can total the full stock lengths first, then compare that quantity with the cut plan and expected remnant. | Material or alloy: Carbon steel; Shape: Square bar; Width or side: 40 mm; Length: 6 m; Quantity: 10 | Total theoretical weight748.8 kg | |
| Support-bracket materialSteel flat bar, 6 × 0.375 in × 20 ftBracket material weight begins with the uncut flat bar; holes, end cuts, galvanizing, and packaging are later adjustments. | Material or alloy: Carbon steel; Shape: Flat bar; Thickness: 0.375 in; Width or side: 6 in; Length: 20 ft; Quantity: 18 | Total theoretical weight1,242.401644 kg | |
| Skid fabricationSteel flat bar, 100 × 12 mm × 6 mProcurement comparisons stay consistent when nominal width, thickness, stock length, quantity, and density basis are the same. | Material or alloy: Carbon steel; Shape: Flat bar; Thickness: 12 mm; Width or side: 100 mm; Length: 6 m; Quantity: 24 | Total theoretical weight1,347.84 kg |
Frequently asked questions
What steel density should I use?
Use a documented value for the exact grade when it matters. A general steel value may support a preliminary estimate, but alloy chemistry and product data should govern the final assumption.
Does the calculator include steel tolerances?
No. It calculates from the dimensions entered. Apply the relevant product tolerance or supplier data separately when minimum, maximum, or contractual mass matters.
Can theoretical steel weight be used on a purchase order?
It can support planning, but the purchase order should state the governing grade, dimensions, tolerance, quantity, and commercial weighing or pricing basis.
Should galvanizing be included?
Only if a separate, source-backed coating allowance is added. The base geometry calculation does not automatically include zinc, paint, scale, or other surface layers.
Sources
Circumference, Area and Volume (Opens in a new tab)
National Institute of Standards and Technology
- Supports
- Geometry or calculation formula
- Checked
NIST Guide to the SI, Appendix B.8 and footnotes (Opens in a new tab)
National Institute of Standards and Technology
- Supports
- Unit conversion
- Checked
Code of Standard Practice for Steel Buildings and Bridges (Opens in a new tab)
American Institute of Steel Construction
- Supports
- Material density
- Checked