Metal Weight Calculator
Calculate the weight of metal stock by shape — flat bar, round bar, tube, and sheet — for steel, aluminum, brass, and copper.
How metal weight is calculated:
Metal weight is simply volume multiplied by density. The formula changes depending on the shape of the stock.
Volume formulas by shape:
Flat bar / plate:
Volume = Length × Width × Thickness
Round bar (solid rod):
Volume = π × (Diameter/2)² × Length
Round tube (hollow):
Volume = π × Length × [(OD/2)² − (ID/2)²]
Sheet / plate:
Volume = Length × Width × Thickness
Then: Weight = Volume × Density
Metal densities:
| Metal | lb/in³ | kg/cm³ | g/cm³ |
|---|---|---|---|
| Mild steel | 0.284 | 0.00785 | 7.85 |
| Stainless steel (304) | 0.289 | 0.00800 | 8.00 |
| Aluminum (6061) | 0.098 | 0.00271 | 2.71 |
| Brass | 0.307 | 0.00849 | 8.49 |
| Copper | 0.323 | 0.00894 | 8.94 |
| Cast iron | 0.260 | 0.00720 | 7.20 |
| Titanium | 0.163 | 0.00451 | 4.51 |
Worked example — steel flat bar:
1-inch wide × 1/4-inch thick × 48 inches long mild steel:
- Volume = 48 × 1.0 × 0.25 = 12.0 in³
- Weight = 12.0 × 0.284 = 3.41 lbs
Worked example — aluminum round bar:
1-inch diameter × 36 inches long 6061 aluminum:
- Volume = 3.14159 × (0.5)² × 36 = 28.27 in³
- Weight = 28.27 × 0.098 = 2.77 lbs
Why this matters in the shop:
- Shipping costs are based on weight — know before you order
- Structural calculations require accurate dead loads
- Comparing materials: aluminum is 1/3 the weight of steel at the same dimensions
- Scrap value is priced per pound — weigh before selling