Round Bar Weight Calculator
Theoretical weight of round bars from diameter, length, quantity and material — live, with PDF download and email options.
Theoretical weight from nominal diameter and the indicative family density. For a quick rule of thumb in steel, kg/m ≈ d²/162.2 (d in mm) — this calculator uses the exact π/4 × d² × ρ instead. Inputs can be entered in mm/m or in/ft.
Accuracy disclaimer: theoretical weights from nominal dimensions and indicative family densities. Actual pieces vary within manufacturing tolerances and the actual chemistry of the melt. Use results for estimation, freight planning and budgeting only — purchase and invoicing use the actual weighed figures and the EN 10204 mill test certificate for the lot.
How It Works
The cross-section of a round bar is a circle: area = π/4 × d² (mm²). Multiplied by density (kg/m³) and divided by 10⁶, that is the kilograms per metre; length and quantity give the total.
The familiar site rule for steel — kg/m ≈ d²/162.2 — is just this formula with ρ = 7850 pre-substituted and π rounded away; it is shown here for reference, but the calculator always uses the exact expression with the density you select.
Densities Used
The material dropdown lists every stocked grade of all 13 families, each with its published typical density (or the family indicative value). The family reference values:
| Material | Density (kg/m³) | Note |
|---|---|---|
| Alloy Steel | 7,850 | |
| Aluminium | 2,700 | 2.66 – 2.81 by grade |
| Brass & Bronze | 8,500 | varies 8.4 – 8.8 by grade |
| Carbon Steel | 7,850 | |
| Copper & Copper Nickel | 8,940 | pure copper; CuNi ≈ 8.9 |
| Duplex & Super Duplex Steel | 7,800 | 2205 / super duplex ≈ 7.8 g/cm³ |
| Hastelloy | 8,890 | C276; other grades vary — see table |
| Inconel & Incoloy | 8,400 | varies by grade — see table |
| Monel | 8,800 | Monel 400 ≈ 8.8; K500 ≈ 8.44 g/cm³ |
| Nickel Alloys | 8,900 | Nickel 200/201 |
| Stainless Steel | 8,000 | austenitic 8.0; ferritic / martensitic 7.7 – 7.75 |
| Tantalum & Speciality Metals | 16,600 | Ta 16.6 – 16.9; Zr 6.51; Nb 8.57; Bi 9.78; Zn 7.14; Pb 11.34 |
| Titanium | 4,510 | 4.43 (Gr 5) – 4.51 |
Every grade carries its own entry in the dropdown above — for precision work confirm against the grade datasheet, or use Custom density with the grade's exact value.
Bar Sized and Weighed?
Send the diameter, grade and quantity — the desk confirms availability in bars or cut lengths.