Roll Weight Calculator: Net Weight from Diameters, Width & Density
Enter roll OD, core OD, width, and the data-sheet density to estimate the net weight of a wound roll or coil of foam, rubber, film, or tape — for freight quotes, crane and rack limits, and receiving checks.
Built for: freight estimates, rack loading limits, and sanity-checking supplier weights at receiving.
Roll Weight Calculator
How it works — formula, worked example & reference
Formula: W = π/4 × (OD² − ID²) × width × density — the volume of the wound annulus times material density. Add core weight separately for gross weight.
Worked example: OD = 12 in, core = 3 in, width = 36 in, density = 70 lb/ft³ (solid rubber, SG ≈ 1.12): volume = π/4 × 135 × 36 = 3,817 in³ = 2.21 ft³; W = 2.21 × 70 = 154.6 lb.
| Material family | Typical density (lb/ft³) — TDS governs |
|---|---|
| Polyethylene foam | 2–9 |
| Polyurethane foam | 4–25 |
| Neoprene / EPDM sponge | 8–20 |
| Silicone sponge / foam | 12–35 |
| Solid elastomers (SG 1.1–1.6) | 69–100 |
Ranges are typical for orientation; always use the density on the specific material data sheet.
These results are engineering estimates for preliminary material selection; final validation is the responsibility of your engineering team.
Common questions
How do I calculate the weight of a roll of material?
Compute the wound volume from the roll and core diameters and the roll width, then multiply by the material density from the data sheet: W = π/4 × (OD² − ID²) × width × density.
Where do I get the density?
From the material TDS. Foams list density directly in lb/ft³ (pcf); solid rubbers usually list specific gravity — multiply SG by 62.4 to get lb/ft³.
Does this work as a coil weight or coil length calculator?
Yes — the same wound-annulus geometry applies to any coiled material. Pair it with our roll length calculator to get footage from the same measurements.
Why does my scale reading differ?
Core weight, packaging, winding tension, and density tolerance all add up. Add the core’s own weight for gross figures — this tool returns net material weight.