How do I calculate the weight of a full coil from OD and ID?

Coil weight (kg) = π/4 × (OD² − ID²) × width (mm) × 7.85×10⁻⁶, with OD, ID and width in millimeters. A coil of OD 1200 mm, ID 508 mm and width 1250 mm weighs about 9,100 kg (9.1 t). Typical GI coils run 3–8 tons.

How many square meters is one ton of GI coil?

Area per ton = 1000 ÷ (7.85 × thickness in mm + Z/1000). For 0.5 mm Z60 coil: 1000 ÷ (3.925 + 0.06) ≈ 251 m² per ton. For 1.0 mm Z60: about 127 m² per ton.

How many tons of GI coil fit in a container?

A 20ft container typically carries 18–22 tons of coils and a 40ft about 24–26 tons, limited by coil diameter and loading plan. Nikasteel mixes widths, thicknesses and even other products (plates, sections) in one container, with trial orders from 5 tons.

GI Coil Weight Calculator — Sheet, Coil & Meters per Ton

Q: How do I calculate the weight of a GI sheet?

Weight (kg) = thickness (mm) × width (m) × length (m) × 7.85, then add the zinc: coating in g/m² (total both sides, e.g. Z60) adds Z/1000 kg per square meter. A 1.0 × 1219 × 2438 mm sheet weighs about 23.3 kg in base steel; with Z60 coating about 23.5 kg.

Q: Does the zinc coating count in the invoiced weight?

Yes — mills weigh the finished coated coil on a weighbridge, so invoiced weight includes the zinc. Theoretical base-steel values (7.85 t/m³) are for estimation and typically land within a few percent of the weighed weight; the Z-coating selector in the calculator adds the coating weight for a closer estimate.

① Sheet Weight

Per sheet: -- kg

Total: --

kg = (7.85 × t + Z/1000) × width(m) × length(m)

② Full Coil Weight

Coil weight: --

Strip length: --

kg = π/4 × (OD² − ID²) × width × 7.85×10⁻⁶ · typical coils 3–8 t

③ Meters & Area per Ton

Strip length per ton: --

Area per ton: --

1000 kg ÷ kg per meter (or per m²) — for roofing coverage and cost-per-m² math

Thickness	Base kg/m² (7.85×t)	+Z60 kg/m²	+Z275 kg/m²	Common use
0.13 mm	1.02	1.08	1.30	Tube forming, light ducting
0.3 mm	2.36	2.42	2.64	Light profiles
0.5 mm	3.93	3.99	4.21	Roofing sheets, panels
0.8 mm	6.28	6.34	6.56	Roofing, decking
1.0 mm	7.85	7.91	8.13	Ducting, purlins, general
1.5 mm	11.78	11.84	12.06	Purlins, structural panels
2.0 mm	15.70	15.76	15.98	Purlins, cold-formed sections
3.0 mm	23.55	23.61	23.83	Heavy sections
4.0 mm	31.40	31.46	31.68	Structural shapes

Common sheet (mm)	Base kg/sheet	Sheets per ton	Typical order
0.5 × 1000 × 2000	7.85	≈127	Roofing cut-to-length
0.8 × 1219 × 2438	18.66	≈54	Roofing & cladding
1.0 × 1219 × 2438	23.33	≈43	Ducting, general fabrication
1.2 × 1219 × 2438	28.00	≈36	Panels, profiles
1.5 × 1219 × 2438	35.00	≈29	Purlins, brackets
2.0 × 1219 × 2438	46.67	≈21	Structural parts

The Formulas Behind the Calculator

Flat sheet: kg = thickness (mm) × width (m) × length (m) × 7.85 — steel density 7.85 t/m³.
Zinc add-on: coating weight Z (g/m², total both sides per GB/T 2518) adds Z/1000 kg per m². Z275 on 0.5 mm adds ≈ 7% — worth including on thin gauges.
Full coil: kg = π/4 × (OD² − ID²) × width (mm) × 7.85×10⁻⁶. Strip length (m) = coil kg ÷ kg per meter, where kg/m = (7.85 × t + Z/1000) × width (m).
Theoretical vs invoiced: mills invoice on actual weighbridge weight of the finished coated coil, usually within a few percent of theory. How quotes differ on weight basis is covered in our steel price structure guide.

Container Planning Cheat-Sheet

20ft container: ≈ 18–22 tons of coils (limited by coil OD and dunnage)
40ft container: ≈ 24–26 tons
Mixed loads OK: different widths/thicknesses in one coil container, or coils + plates + sections combined — trial orders from 5 tons

FAQ

How do I calculate the weight of a GI sheet?

kg = thickness (mm) × width (m) × length (m) × 7.85, plus Z/1000 kg per m² for the zinc. A 1.0 × 1219 × 2438 mm sheet is ≈ 23.3 kg in base steel.

How heavy is a standard GI coil?

Typical mill coils run 3–8 tons. OD 1200 / ID 508 / width 1250 mm ≈ 9.1 t of base steel; slitted narrower coils scale directly with width.

How many square meters is one ton of 0.5 mm Z60?

≈ 251 m² per ton: 1000 ÷ (7.85 × 0.5 + 0.06). Roofing coverage math uses the same number minus laps and corrugation profile.

Does the zinc coating count in the invoiced weight?

Yes — the weighbridge weighs the finished coated coil, so zinc is in the invoice. Theory values are for estimation; confirm the weight basis on the proforma invoice.

Get Exact Coil Weights & FOB Prices

Send your thickness × width × zinc schedule to [email protected] or WhatsApp +86 191 5745 8011 — we reply with weights, EXW/FOB pricing and delivery time within 24 hours. EN 10204 3.1 MTC with every order. More on coatings in the GI vs GL vs aluzinc guide and the GI coil product page.

GI Coil Weight Calculator