How do you calculate coil weight?

Multiply strip width × coil length × gauge thickness × material density, all in inches and lb/in³. For 48 in × 12000 in × 0.0598 in × 0.2836 lb/in³ the weight is about 9,769 lb.

What density do I use for steel coil weight?

Carbon steel is about 0.2836 lb/in³, as used here. Aluminum is roughly 0.098 and copper about 0.323, so always match density to the grade.

Why is my calculated coil weight different from the mill cert?

Gauge runs within tolerance, coatings and oil add weight, and length is often nominal. A few percent difference between this theoretical figure and a scale weight is normal.

How do I find coil length if I only know weight?

Rearrange the formula: length equals weight divided by width, gauge, and density. That's the basis for converting a weight-priced coil into lineal feet for production planning.

Does this work for aluminum and copper coil?

Yes. The formula is identical; just change the material density input. Swapping steel's 0.2836 for aluminum's ~0.098 gives the lighter coil weight at the same dimensions.

What's the difference between gauge and thickness here?

Gauge is a sizing standard; the input wants the actual decimal thickness in inches. 0.0598 in corresponds to roughly 16-gauge steel, so always convert gauge numbers to their decimal equivalent first.

Metals, Steel, Aluminum & Coil Processing calculator

Coil Weight Calculator

Coil weight is the theoretical mass of a wound metal coil computed from its strip width, total length, gauge thickness, and material density. Coil processors, slitters, stampers, and purchasing teams use it to verify mill certs, plan crane and reel capacity, estimate freight, and convert between weight-priced and footage-priced material. Because a slit coil is billed by the pound but consumed by the foot, a reliable weight figure ties the commercial and production sides together. It also catches mislabeled coils before they hit a press that can't handle the load.

What this calculator does

Calculate coil weight from strip width, coil length, gauge thickness, and material density, so you can plan handling, freight, and bundle weights.
Use it when a material handler or planner needs a coil weight from dimensions before staging, craning, or booking freight.
It multiplies strip width, coil length, gauge thickness, and material density to return the theoretical weight of a flat strip coil in pounds.

Formula used

Coil weight = strip width × coil length × gauge thickness × material density
Keep all dimensions in inches and density in pounds per cubic inch.

Inputs explained

Strip width:
Coil length:
Gauge thickness:
Material density:

How to use the result

Use it to check an incoming coil against its mill cert, size handling and reel equipment, or convert a footage requirement into a weight to order.
It's a theoretical flat-strip calculation; real coil weight varies with thickness tolerance, oil or coating, and density assumptions, so treat it as a close estimate not a billing scale.

Current U.S. benchmarks

The producer price index for steel mill products stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The producer price index for aluminum mill shapes stands at 404.859 (BLS, May 2026), up 36.8% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).

Common questions

How do you calculate coil weight? Multiply strip width × coil length × gauge thickness × material density, all in inches and lb/in³. For 48 in × 12000 in × 0.0598 in × 0.2836 lb/in³ the weight is about 9,769 lb.
What density do I use for steel coil weight? Carbon steel is about 0.2836 lb/in³, as used here. Aluminum is roughly 0.098 and copper about 0.323, so always match density to the grade.
Why is my calculated coil weight different from the mill cert? Gauge runs within tolerance, coatings and oil add weight, and length is often nominal. A few percent difference between this theoretical figure and a scale weight is normal.
How do I find coil length if I only know weight? Rearrange the formula: length equals weight divided by width, gauge, and density. That's the basis for converting a weight-priced coil into lineal feet for production planning.
Does this work for aluminum and copper coil? Yes. The formula is identical; just change the material density input. Swapping steel's 0.2836 for aluminum's ~0.098 gives the lighter coil weight at the same dimensions.

Last reviewed 2026-05-12.