Steel Weight Calculator
A steel weight calculator multiplies length × width × thickness (in) by 0.284 lb/in³: a 48 × 6 × 0.25 in plate weighs about 20.45 lb.
How to calculate steel weight
A steel weight calculator finds the weight of a solid rectangular piece of carbon steel. Enter the length, width, and thickness in inches. The tool multiplies the three to get cubic inches, then multiplies by 0.284 pounds per cubic inch.
Think of a block of steel the size of your plate. Fill that block with cubes of steel, each one an inch on a side. Each cube weighs 0.284 lb, so the weight is the number of cubes times 0.284.
The formula in plain words
- Volume in cubic inches = length × width × thickness.
- Weight in pounds = volume × 0.284.
All three dimensions must be in inches. For a long bar given in feet, multiply by 12 first.
Worked example: a base plate
A plate is 48 in long, 6 in wide, and 0.25 in thick.
- Volume: 48 × 6 × 0.25 = 72 in³
- Weight: 72 × 0.284 = 20.45 lb
Worked example: a larger sheet
A sheet is 96 in by 12 in and 0.5 in thick.
- Volume: 96 × 12 × 0.5 = 576 in³
- Weight: 576 × 0.284 = 163.58 lb
Worked example: flat bar
A flat bar is 120 in long, 4 in wide, and 3/16 in (0.1875 in) thick.
- Volume: 120 × 4 × 0.1875 = 90 in³
- Weight: 90 × 0.284 = 25.56 lb
Plate weight per square foot
For a 12 in by 12 in piece:
| Thickness | Weight per sq ft |
|---|---|
| 1/4 in | 10.22 lb |
| 3/8 in | 15.34 lb |
| 1/2 in | 20.45 lb |
| 3/4 in | 30.67 lb |
| 1 in | 40.90 lb |
Weight scales in a straight line with thickness, so doubling the thickness doubles the weight. To find a whole plate, multiply by the area in square feet.
How to measure and what to enter
Measure the finished piece with a tape or caliper. For plate, use the actual thickness on the mill certificate if you have it, since plate can vary slightly from nominal. For a large cut, subtract the area of any holes. A 1 in diameter hole through a 1/2 in plate removes about 0.39 in³, or 0.11 lb.
If you are ordering, remember that the supplier may sell by the sheet or by the pound. Sheet weights include the full sheet, not just the part you cut from it.
Why the weight matters
Weight decides how you move the piece. A 163 lb sheet is a two-person lift, or a job for a hoist. It also affects shipping charges, which are usually by weight, and the load on whatever supports it. A plate bolted to a wall or hung from a ceiling needs fasteners and structure rated for it, so have an engineer check anything that carries people or equipment.
Other metals
The 0.284 figure is tuned for carbon steel. Stainless steel is a little different, and aluminum is only about a third as heavy for the same size. If you work with other metals, the formula is the same, but the density changes. Use the number from the supplier’s data sheet and the same multiplication of volume times density.
Steel sold with a coating, such as galvanized sheet, weighs slightly more than the bare metal because of the zinc. That difference is small for most jobs.
Common mistakes
- Using feet for one dimension and inches for the others. Convert everything to inches.
- Using the wrong material. This tool uses carbon steel density. Aluminum and stainless need different numbers.
- Entering nominal thickness for thin sheet. Gauge numbers do not equal inches, so look up the actual thickness.
- Forgetting cutouts. Holes and slots remove weight.
- Applying it to pipe or beams. Hollow or shaped sections need other formulas.
Related calculators
For bolts and fasteners, see the bolt weight calculator. Structural shapes are covered by the I-beam weight calculator, and reinforcing bar by the rebar weight calculator.
Frequently asked questions
How do I calculate the weight of a steel plate?
Multiply length, width, and thickness in inches to get cubic inches, then multiply by 0.284 lb per cubic inch. A 48 × 6 × 0.25 in plate is 72 in³, which weighs 20.45 lb.
How much does a square foot of steel plate weigh?
At 0.284 lb/in³, a 12 in by 12 in piece weighs 10.22 lb for a 1/4 in thickness, 15.34 lb at 3/8 in, 20.45 lb at 1/2 in, 30.67 lb at 3/4 in, and 40.90 lb at 1 in.
What steel density does the calculator use?
It uses 0.284 lb/in³, which is about 490 lb/ft³, the usual figure for carbon steel. Stainless runs slightly different and aluminum is roughly a third as heavy.
Does it work for pipe, angle, or I-beams?
No. It works for solid rectangular pieces such as plate, flat bar, and sheet. For beams use published weights per foot, or the I-beam weight calculator on this site.
Do I need to add anything for cutouts?
Holes and cutouts remove weight. Calculate the solid piece, then subtract the volume of each hole times 0.284.
Estimates only. Verify quantities with your supplier before purchasing.