Steel Coil Weight Calculator
Calculate coil weight and the wound strip length from outer diameter, inner diameter, width and strip thickness — with that grade's own measured density. A real GET form: computes correctly with JavaScript off.
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Coil weight — frequently asked
How is the strip length derived from the coil dimensions?
The wound cross-section is the annulus between outer and inner diameter; dividing its area by the strip thickness gives the length: L = π (OD² − ID²) ⁄ (4 t).
Why must the inner diameter be smaller than the outer diameter?
Equal diameters would mean zero wound material. The calculator refuses that input and names the bound instead of returning a meaningless zero.
Does the calculation account for gaps between the wraps?
No — it assumes a tightly wound coil, the standard mill convention. A loosely wound or telescoped coil weighs the same but measures a larger outer diameter, so measure OD on a tight coil.