← Back to Bead BoardSteel plate weight chart
Pre-computed plate weights by thickness so you don't have to punch numbers into a calculator every time. Steel, stainless, and aluminum from 1/16" to 1". Weight per square foot, kg/m², and full 4′×8′ sheet weights.
Quick answer
1/4 inch A36 steel plate weighs 10.21 lb per square foot. A standard 4x8 sheet of quarter-inch plate is about 327 lb.
Steel plate weight per square foot
Mild steel (ASTM A36) at 0.2836 lb/in³ (7.85 g/cm³). The standard structural and fabrication plate in most welding shops.
Stainless steel plate weight per square foot
304 stainless steel at 0.289 lb/in³ (8.0 g/cm³). The most common stainless grade in fab shops. Used for food equipment, handrails, and anything that needs to resist corrosion.
Aluminum plate weight per square foot
6061-T6 aluminum at 0.0975 lb/in³ (2.70 g/cm³). Standard alloy for structural aluminum fab work, jigs, and fixtures.
Quick formulas
If your thickness isn't in the chart, multiply the decimal thickness in inches by the constant for your material:
- Steel: lb/ft² = thickness × 40.84
- Stainless (304): lb/ft² = thickness × 41.62
- Aluminum (6061): lb/ft² = thickness × 14.04
These constants are density × 144 (the number of square inches in a square foot). Multiply the result by your piece's area in square feet to get the total weight.
Need weight for a specific piece size?
This chart gives you weight per square foot. To calculate the weight of a specific plate with custom dimensions, use the interactive calculator for your material:
Questions welders keep asking
How much does 1/4 inch steel plate weigh per square foot?
1/4" mild steel plate weighs 10.21 lb per square foot. That is thickness (0.25") times the steel weight constant (40.84). A full 4’×8’ sheet of 1/4" plate weighs about 327 lb.
How do I calculate plate weight for a custom size?
Find the lb/ft² value from the chart, then multiply by your piece’s area in square feet. Example: a 2’×3’ piece of 3/8" steel plate = 15.31 lb/ft² × 6 ft² = 91.9 lb. For pieces measured in inches, divide length × width by 144 to get square feet first.
Does stainless steel weigh more than mild steel?
Slightly. 304 stainless has a density of 0.289 lb/in³ compared to 0.2836 lb/in³ for A36 mild steel, about 1.9% heavier. At 1/4" thickness, stainless is 10.40 lb/ft² versus 10.21 lb/ft² for mild steel. The difference is small enough that most shops use the same weight estimate for both unless they are doing precise material costing.
What is the weight of a 4x8 sheet of 3/8 plate?
A 4’×8’ sheet of 3/8" mild steel plate weighs about 490 lb. Stainless steel (304) at the same thickness weighs about 499 lb. You need a forklift or at least two people and a crane for anything 3/8" and above in a full sheet.
Are these plate weights exact?
They are calculated from published density values (MatWeb ASTM A36, AISI 304, 6061-T6) and are accurate for estimating and quoting. Actual plate from the mill can vary by 2–5% due to rolling tolerances, and hot-rolled plate is typically on the heavy side. If you need certified weights, weigh the piece on a floor scale.