Sheet Metal Area Calculator computes area take-offs for flat sheets and coils. Switch between Sheets and Coil workflows to plan purchases, estimate waste, and report in both metric and imperial.
About workflows (Sheets vs Coil). Use Sheets when you know the sheet width, length, and quantity. Use Coil when you have a roll (coil width and total uncoiled length) and optionally a target sheet length to estimate the number of sheets.
About units. Metric inputs for sheet/coil width and sheet length use millimeters (mm), while coil length uses meters (m). In imperial, sheet/coil width and sheet length use inches (in), while coil length uses feet (ft). Results display in the active system first (m² or ft²) and the secondary system below.
About waste / allowance. Add a percentage to account for cutting, kerf, handling, or layout losses. The tool reports Gross Area (before waste) and Net Area (after waste). Set waste to 0% for theoretical area.
Conversion / Calculation. Multiplying sheet or coil width by length gives the base area, multiplying by quantity gives the gross area, and subtracting waste gives the net area. In Coil mode, dividing total coil length by a target sheet length provides the estimated number of sheets.
Formulas:
- A_sheet = W × L (area per sheet or strip)
- A_gross = A_sheet × N (total gross area for sheets)
- A_strip = W × L_total (total area for coils)
- A_net = A_total × (1 − Waste%/100) (net area after waste)
- Sheets_est = ⌊L_total / L_target⌋ (estimated count from coil with target sheet length)
Examples:
- Example 1 – Sheets workflow: W = 1250 mm, L = 2500 mm, N = 10, Waste = 3% →
A_sheet = 1.25 × 2.5 = 3.125 m²,
A_gross = 31.25 m²,
A_net ≈ 30.31 m². - Example 2 – Coil workflow: W = 1250 mm, L_total = 100 m, Waste = 2% →
A_strip = 1.25 × 100 = 125 m²,
A_net = 122.5 m². - Example 3 – Coil plus target sheets: same coil, target L_target = 2500 mm →
Sheets_est = ⌊100 / 2.5⌋ = 40 sheets.
Corresponding tools. For mass/weight, use the Plate Weight Calculator or Steel Weight Calculator. For beam/plate section data, try the Structural Steel Section Properties Calculator. For fabrication estimating, see the Welding Cost Calculator.
