Plate Weight Calculator
Plate weight = length × width × thickness × the metal's density. Carbon-steel plate weighs about 40.8 lb per square foot per inch of thickness, so a 4 × 8 ft sheet of ¼ in steel plate is about 10.2 lb/ft², or roughly 327 lb. For bars, use the Metal Weight Calculator.
How it's calculated: Weight = length × width × thickness × density × number of plates (carbon steel 7,850 kg/m³).
Result appears here
Fill in the fields and press Calculate.
Formula, calculation, assumptions and sources
Weight = Length × Width × Thickness × material density × quantity
Run the calculation to see each step with your own numbers.
A 1/4 in carbon-steel plate, 4 ft × 8 ft.
1/4 in steel plate weighs ≈ 10.2 lb/ft²
4 × 8 = 32 ft² → ≈ 327 lb
- Flat rectangular plate of uniform thickness — no bevels, holes or camber.
- Nominal alloy density; plate thickness tolerance not applied.
- Quick rule for steel plate?
- Carbon-steel plate weighs about 40.8 lb/ft² per inch of thickness (so 1/2 in ≈ 20.4 lb/ft², 1/4 in ≈ 10.2 lb/ft²). Aluminium is roughly a third of that.
- Do holes or cut-outs reduce the weight much?
- A few bolt holes are negligible. A large cut-out or a plate burned to a shape does matter — subtract the removed area and run it again, or weigh the offcut.
- How much does a 4×8 sheet of 1/4 inch steel plate weigh?
- About 327 lb. Quarter-inch carbon-steel plate weighs roughly 10.2 lb per square foot, and a 4 × 8 ft sheet is 32 ft². Aluminium plate of the same size weighs about a third as much.
- How much does aluminum plate weigh per square foot?
- About 14 lb per square foot per inch of thickness at 2,700 kg/m³, so ¼ in aluminium plate is roughly 3.5 lb/ft² — about a third of the weight of steel plate the same size.
Densities
Metal densities from the ASM Metals Reference Book / Machinery's Handbook: carbon steel 7,850 · stainless ~7,950 · aluminium 2,700 · copper 8,960 · brass ~8,500 · cast iron ~7,200 kg/m³.
About the Plate Weight Calculator
The Plate Weight Calculator gives the weight of a flat rectangular metal plate from its length, width, thickness, quantity and material, and reports the weight per square foot. It assumes a plain plate with no bevels, holes or camber. For bar stock use the Metal Weight Calculator; for pipe, the Pipe Weight Calculator.
What you enter
- Length
- Width
- Thickness
- Number of plates
- Material
What you get back
- Total weight — the exact result of the calculation.
- Weight per square foot — the exact result of the calculation.
The formula, a worked example, the assumptions behind it and the sources are shown in full below the calculator.
Related calculators
- Metal Weight Calculator — Weight of a metal bar, sheet or section from its dimensions and alloy.
- Pipe Weight Calculator — Weight of a length of pipe from its size, wall thickness and material.
- Rebar Calculator — Rebar quantity, spacing and lineal feet for a slab or footing grid.
Part of the Materials calculators.