Free Calculator

Metal Weight Calculator
for Machine Shops

Pick a shape, pick an alloy, enter dimensions. Get weight in pounds and kilograms plus approximate material cost. No signup, no vendor bias.

Your numbers

Dimensions
Weight
2.67 lb
1.21 kg
Breakdown
ShapeRound Bar
Material1018 Mild Steel
Density0.2836 lb/in³
Volume9.425 in³
Weight (lb)2.67 lb
Weight (kg)1.21 kg
Approximate material cost
$2.14$4.01
Based on $0.80–$1.50/lb average. Actual prices vary by supplier, quantity, and form.

How to calculate metal weight

Metal weight is volume times density. The trick is getting volume right for the shape you're buying, and using the correct density for your specific alloy.

Volume formulas by shape

Round bar:π × (diameter/2)² × length. A 1" round bar 12" long has a volume of 9.42 cubic inches.

Flat bar / plate:width × height × length. Straightforward rectangular cross-section.

Square bar:side² × length.

Hex bar:2.598 × (across-flats/2)² × length. The 2.598 factor accounts for the hexagonal cross-section area.

Tubing:π × ((OD/2)² − (ID/2)²) × length, where ID = OD − 2 × wall thickness.

Common material densities

Steel (1018, 4140, 4340): 0.2836 lb/in³ (7.85 g/cm³). Most carbon and alloy steels are within 1% of this number.

Aluminum 6061-T6: 0.0975 lb/in³ (2.70 g/cm³). About a third the weight of steel.

304 Stainless: 0.2888 lb/in³ (7.99 g/cm³). Slightly heavier than carbon steel due to the nickel and chromium content.

Ti-6Al-4V: 0.160 lb/in³ (4.43 g/cm³). About 57% of steel's weight with comparable strength.

Why material cost is a range

Metal prices vary by supplier, quantity, form (hot-rolled vs. cold-drawn vs. precision-ground), and current market conditions. The ranges shown here reflect typical US distributor pricing for cut-to-length bar stock in small quantities. Buying full 20' bars, mill-direct, or from a service center at volume will shift pricing significantly.

Quick reference: weight per foot of round bar

A common shortcut for steel round bar: weight per foot ≈ diameter² × 2.67 lb/ft. So a 2" round is about 10.68 lb/ft. This calculator does the exact math for any shape, length, and alloy.

Frequently asked questions

Use the formula: weight = pi times (diameter/2) squared times length times density. For steel, density is 0.2836 lb per cubic inch. A 1 inch round bar 12 inches long weighs about 2.67 pounds. This calculator does the math for you with any alloy and any shape.

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