How much does a roll of steel weigh? Most steel rolls — also called steel coils — weigh between 3 and 28 tons (about 6,600 to 61,700 pounds). Light-gauge coils for roofing and cladding are often 3 to 5 tons, general-purpose hot-rolled coils are commonly 10 to 20 tons, and heavy industrial coils can reach 25 to 30 tons or more. There is no single standard weight, because a coil’s weight is decided by just four things: its thickness, its width, how much steel is wound on it, and the type of steel. If you know those four numbers, you can calculate the weight exactly with the formulas below — no guessing and no calculator website needed.
First, “roll” and “coil” mean the same thing here
In the steel trade, a “roll of steel” and a “coil of steel” are the same product: a long, flat strip of steel wound into a roll around a core, like a giant roll of tape. Mills sell steel this way because a coil is easier to transport, store, and feed into machines than thousands of loose sheets.
- A hardware-store “roll” is not a mill coil. Thin steel flashing, strapping, or wire sold in small rolls at a shop may weigh only a few pounds or a few dozen pounds. Those are cut-down products. When factories, suppliers, and shipping documents talk about a roll of steel, they almost always mean a full mill coil weighing several tons.
- The core, wrapping, and pallet add weight. The steel itself is the number in the tables below. A steel or cardboard core, protective wrapping, banding, and a pallet can add tens to hundreds of pounds on top. For shipping, always use the gross weight on the mill certificate or scale ticket, not just the calculated steel weight.
What actually decides the weight
A coil is just a volume of steel. Weight is volume multiplied by density, and steel’s density is very consistent: about 7,850 kilograms per cubic metre (7.85 grams per cubic centimetre, or 0.284 pounds per cubic inch) for ordinary carbon steel. Stainless steel is slightly denser, around 8,000 kg/m³, which makes the same coil roughly 2% heavier — a difference that matters for pricing but rarely changes a transport decision on its own.
That leaves four variables:
| Variable | What it does to the weight | Typical range |
|---|---|---|
| Thickness (gauge) | Thicker steel = heavier per square foot, and usually a heavier coil | 0.4 mm to 12 mm+ |
| Width | Wider strip = more steel in every turn of the coil | 600 mm to 2,000 mm (24 to 79 inches) |
| Length of strip wound on the coil | Longer strip = heavier coil, even at the same thickness and width | Hundreds to thousands of metres |
| Steel type and coating | Density differences and coatings (zinc, paint) shift the total slightly | Carbon, galvanized, stainless, color-coated |
Thickness is the single most powerful lever. Double the thickness at the same width and length, and you double the weight. Width works the same way. Length is the sneaky one: two coils can look identical from the outside yet weigh very differently, because one simply has more steel wound inside it.
The two formulas (use the one that matches your measurements)
You only need one of these, depending on what the supplier gives you. Both give the same answer when the measurements describe the same coil.
Formula 1: From thickness, width, and strip length
Use this when you know how long the strip is.
Metric: Weight (kg) = thickness (mm) × width (mm) × length (m) × 7.85 ÷ 1,000
Imperial (correct version): Weight (lb) = width (in) × thickness (in) × length (ft) × 3.41
The imperial shortcut matters, so note it carefully: some web pages print the imperial formula with a factor of 0.284 and length in feet, which is wrong by a factor of 12 — it forgets to convert feet into inches. The density 0.284 lb/in³ only works when every dimension is in inches. Convert length from feet to inches first (multiply by 12), and 0.284 × 12 = 3.41. If you use 0.284 with feet, your answer will come out twelve times too light, and a 30,000-pound coil will look like a 2,500-pound one. That is a dangerous mistake for a truck booking.
Formula 2: From outer diameter, inner diameter, and width
Use this when you only have the coil’s outside and inside diameters — the measurements you can actually take on a coil sitting in a yard.
Weight (kg) = (π ÷ 4) × (outer diameter² − inner diameter²) × width × 7,850, with all diameters and width in metres.
This formula treats the coil as a hollow cylinder: the steel is the ring between the outer edge and the core hole. It is the practical formula for buyers, because outer diameter, inner diameter (usually 508 mm or 610 mm, i.e. 20 or 24 inches), and width are printed on almost every coil label and mill certificate.
Worked examples (check these against any calculator)
Example 1: A standard hot-rolled coil, by diameter
A coil with an outer diameter of 1,200 mm, an inner diameter of 508 mm, and a width of 1,250 mm:
- Outer diameter squared: 1.2² = 1.44; Inner diameter squared: 0.508² = 0.258; Difference: 1.44 − 0.258 = 1.182; Weight = 0.7854 × 1.182 × 1.25 × 7,850 = about 9,100 kg, or 9.1 metric tons (about 20,100 lb)
That is a very typical export coil: big enough to be economical, small enough to load two to a container (see the transport section below).
Example 2: A light-gauge coil, by strip length
A thin coil, 0.5 mm thick, 1,000 mm wide, with 500 metres of strip:
Weight = 0.5 × 1,000 × 500 × 7.85 ÷ 1,000 = about 1,963 kg, or just under 2 tons
This is the kind of coil used for light panels and cladding — and it shows why “standard weight” is meaningless without dimensions. Same width family, very different weight, because the strip is thin and short.
Example 3: An American-size coil, in pounds
A coil 48 inches wide, 0.125 inches (1/8 inch) thick, with 1,500 feet of strip:
Weight = 48 × 0.125 × 1,500 × 3.41 = about 30,700 lb, or about 15.4 US tons
If you ran the same numbers with the faulty 0.284 factor and feet, you would get about 2,560 lb — wrong, and obviously wrong the moment you picture a coil that size. Always sanity-check: a full-size mill coil in the thousands of pounds, not hundreds.
Weight by coil type
The table below gives the ranges most mills and suppliers actually work with. Treat these as planning ranges, not guarantees — a specific coil’s mill certificate is the final word.
| Coil type | Typical thickness | Typical width | Typical weight |
|---|---|---|---|
| Light-gauge / color-coated (PPGI) | 0.3–0.8 mm | 600–1,250 mm | 3–8 tons (6,600–17,600 lb) |
| Cold-rolled steel | 0.3–3.0 mm | 600–1,250 mm | 5–20 tons (11,000–44,100 lb) |
| Galvanized steel | 0.4–4.0 mm | 800–1,500 mm | 5–15 tons (11,000–33,100 lb) |
| Stainless steel | 0.5–5.0 mm | 600–1,300 mm | 5–15 tons (11,000–33,100 lb) |
| Hot-rolled steel | 1.5–12.0 mm | 1,000–2,000 mm | 10–28 tons (22,000–61,700 lb) |
| Heavy structural / plate coil | 6.0 mm and up | 1,500–2,000 mm | 20–30+ tons (44,100–66,100+ lb) |
Two patterns stand out. First, hot-rolled coils are the heaviest common type, because they are thick and wide. Second, color-coated and light-gauge coils are the lightest, even though they look just as large — the steel inside them is simply much thinner. Never judge a coil’s weight by its diameter alone.
Weight per square foot by gauge
If you buy, cut, or price steel by the sheet rather than by the coil, this table is the one to keep. Weight per square foot rises in direct proportion to thickness: every 0.001 inch of thickness adds about 0.041 lb/ft².
| Gauge (approx.) | Thickness | Weight per square foot |
|---|---|---|
| 24 gauge | 0.024 in (0.61 mm) | about 0.98 lb/ft² |
| 20 gauge | 0.036 in (0.91 mm) | about 1.47 lb/ft² |
| 18 gauge | 0.048 in (1.22 mm) | about 1.96 lb/ft² |
| 16 gauge | 0.060 in (1.52 mm) | about 2.45 lb/ft² |
| 14 gauge | 0.075 in (1.90 mm) | about 3.07 lb/ft² |
| 12 gauge | 0.105 in (2.67 mm) | about 4.29 lb/ft² |
| 11 gauge | 0.120 in (3.05 mm) | about 4.91 lb/ft² |
| 10 gauge | 0.135 in (3.43 mm) | about 5.52 lb/ft² |
Gauge numbers are not perfectly standard — the same gauge can mean a slightly different thickness for sheet, plate, and wire, and galvanized gauge includes the coating. For an exact job, use the measured thickness in inches or millimetres, not the gauge label alone. A quick check: a 4 × 8 foot sheet of 1/4-inch steel weighs about 40.8 lb/ft² × 32 ft² = about 1,306 lb. If your estimate is nowhere near that, recheck your units before you order.
How many coils fit on a truck or in a container
Weight, not size, is usually what limits a load. The practical limits most shippers plan around are:
| Transport | Practical payload limit | What that means for coils |
|---|---|---|
| 20-foot shipping container | about 20–24 tons (varies by route and carrier) | 2 coils of 10 tons, or 4 coils of 5 tons |
| 40-foot container | about 26–28 tons payload | rarely more than 2–3 mill coils, and weight still binds first |
| Flatbed truck (US, varies by state) | about 40,000–48,000 lb gross payload for the load, roughly 20–24 US tons | 1 heavy coil, or 2 medium coils, within axle limits |
| Forklift / crane capacity | check the machine’s rating plate, not a guess | a 10-ton coil needs a 10-ton-plus rated lift, with margin |
Three rules follow from this. First, never plan a load by counting coils — plan it by adding up tons. Second, a coil’s weight is concentrated in a small footprint, so axle weights and container floor loading matter as much as the total. Third, if a supplier quotes a coil at “about 15 tons” and your container limit is 20 tons, you cannot safely add a second 10-ton coil to the same container. Get the scale weight first.
Why the calculated weight and the scale weight differ
A calculated weight that is 1–3% off the scale weight is normal, not a sign that you did the maths wrong. The usual causes are:
- Thickness tolerance. Mills allow a small tolerance around the nominal thickness, often a few percent. A coil rolled slightly thick weighs slightly more.
- Coating weight. Galvanizing adds zinc, and paint adds a paint system. On thin steel, the coating is a meaningful share of the total.
- The core and packaging. A steel core alone can weigh hundreds of pounds. Wrapping, banding, and pallets add more.
- Measurement error. Outer diameter is hard to measure exactly on a wrapped coil, and a small diameter error moves the Formula 2 result noticeably.
- Density differences. Stainless and some alloys are denser than carbon steel, as noted above.
For buying and selling, steel is priced by actual scale weight, so the mill certificate and the weighbridge settle every argument. For planning — trucks, cranes, racking, and cost estimates — the calculated weight is exactly what you need, with a small margin added.
Mistakes to avoid
- Using diameter alone to guess weight. Two coils with the same outer diameter can differ by many tons if one is wound with thicker or longer strip.
- Mixing up tons. A US (short) ton is 2,000 lb, a metric tonne is 2,204.6 lb, and a UK (long) ton is 2,240 lb. A “15-ton coil” means three different weights depending on who wrote it. Always confirm which ton a quote uses.
- Using the wrong imperial factor. As shown above, 0.284 only works with inches throughout. With feet, use 3.41.
- Forgetting the gross weight. Booking transport on net steel weight and then discovering the core and packaging push you over the limit is an expensive, avoidable surprise.
- Trusting a single web table without dimensions. Any table that gives one weight for “a roll of steel” without thickness, width, and length or diameters is a rough average, not a specification for your coil.
What to ask your supplier
If you only ask one question, ask for the mill certificate. It should list thickness, width, coil weight (net and gross), inner and outer diameter, and the heat or batch number. With those numbers you can verify the weight with Formula 2 in under a minute, confirm the coil fits your machine’s uncoiler capacity, and book transport with confidence. If a supplier cannot provide them, that is itself useful information.
Frequently asked questions
How much does a standard roll of steel weigh?
There is no single standard, but the most common range is 5 to 20 tons (11,000 to 44,100 lb). Light-gauge coils sit at the low end, hot-rolled coils at the high end.
How much does a roll of steel weigh in pounds?
Multiply tons by 2,000 for US tons or by 2,204.6 for metric tonnes. A 10-metric-tonne coil is about 22,046 lb; a 10-US-ton coil is 20,000 lb.
How do I calculate the weight of a steel coil from its dimensions?
Use thickness × width × strip length × density (Formula 1), or the outer-diameter and inner-diameter formula (Formula 2) if you only have diameters. Both are worked out with real numbers above.
Does a stainless steel coil weigh more than a carbon steel coil of the same size?
Yes, slightly — about 2% more, because stainless steel’s density is around 8,000 kg/m³ versus 7,850 kg/m³ for carbon steel.
How heavy is the heaviest steel coil?
Individual mill coils over 30 tons (66,100 lb) exist for heavy plate and structural work, but they need special handling, cranes, and transport permits. Most mills cap routine coils well below that.
Can I lift a steel coil with a regular forklift?
Only if the forklift is rated for the coil’s full gross weight with margin, and fitted for coil handling. A standard warehouse forklift rated at 5,000 lb cannot lift a 10-ton coil. Check the rating plate, not the size of the machine.
Why do two coils that look the same weigh different amounts?
Because weight depends on thickness and on how much strip is wound inside, neither of which you can see from the outside. Diameter alone tells you almost nothing about weight.
Is coil weight the same as shipping weight?
No. Coil weight is usually the net steel weight. Shipping weight is gross: steel plus core, wrapping, banding, and pallet. Use gross weight for every transport booking.
Bottom line
How much does a roll of steel weigh? Plan on 3 to 28 tons for a normal mill coil, find your coil’s place in that range from its thickness, width, and length or diameters, and verify it against the mill certificate before you buy transport or book a crane. The formula takes a minute; the mistake it prevents — an overloaded truck, an undersized crane, or a container turned away at the port — costs far more than that minute.
