Material Weight Calculator

Estimate material weight

Choose the material and stock shape, then enter your dimensions.

Round bar: enter outside diameter and length.

Approximate preset: 7,860 kg/m³. Select Custom material / density to enter your supplier’s value.

Weight per piece
10.70505922 lb / 4.85573318 kg
Total weight (1 piece)
10.70505922 lb / 4.85573318 kg
Volume per piece
37.69911184 in³
Weight per length
10.70505922 lb/ft / 15.93088314 kg/m

View formula

Volume = π / 4 × OD² × length. Mass (kg) = volume (m³) × 7,860 kg/m³. Pounds = kg / 0.45359237. Total = per-piece mass × quantity.

Calculate weight from material, length and diameter

A round-bar weight estimate starts with volume. Enter the full outside diameter and the length in one unit system. The calculator converts those dimensions to metres, calculates cubic metres and multiplies by density in kg/m³. It then displays both kilograms and pounds.

Round bar and tube weight formulas

Solid round bar: V = π × OD² × L / 4.

Tube: V = π × (OD² − ID²) × L / 4. If you enter wall thickness t, ID = OD − 2t. The wall must be smaller than half the outside diameter.

Rectangular or square bar: V = width × thickness × length. For square stock, enter the same width and thickness.

Hexagonal bar: V = (√3 / 2) × AF² × L, where AF is measured across the flats, not the corners.

For every shape, mass = volume × density. Total weight is per-piece weight multiplied by the number of identical pieces. “Weight” here means estimated mass in kg or lb, not force in newtons.

Worked example: a 2-inch steel round bar

For a solid bar with OD 2 in and length 12 in, the dimensions are 0.0508 m and 0.3048 m. With the general carbon-steel preset of 7,860 kg/m³, the volume is approximately 0.000617778 m³. The estimated mass is approximately 4.856 kg, or 10.705 lb per piece. A quantity of two doubles that estimate.

Choose the correct material density

Different alloys and conditions have different densities. The general aluminium preset is 2,730 kg/m³; 304 stainless is 7,900 kg/m³; C38500 brass is 8,470 kg/m³; and general copper is 8,890 kg/m³. Select Custom material / density when you have a supplier value for your exact grade.

This is an ideal straight-stock estimate. Holes, pockets, chamfers, threads, coatings, welds, mill tolerances and packing are not included unless represented by the dimensions. For a finished part with multiple features, use its measured or CAD volume and the correct density.

Density references: Austral Wright aluminium, carbon steel and copper overview; 304 stainless steel data; C38500 brass data. Presets are approximate values, not a specification for every alloy.

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