Steel weight calculator: steel plate and round bar mass
Calculate steel plate, solid round bar or tube mass using dimensions and nominal density. See a worked steel plate example and the difference between kg and newtons.
Steel plate weight formula
For millimetre dimensions and density in g/cm³: mass (kg) = length × width × thickness × density ÷ 1,000,000. The default carbon-steel reference density is 7.85 g/cm³, equivalent to 7,850 kg/m³.
Carbon steel is not the same as stainless steel
The 304 stainless-steel model uses 7.93 g/cm³ instead of 7.85. Enter the grade-specific density if available. Theoretical mass is not a mill certificate or an actual weighing result; thickness tolerance, alloy composition and coatings change delivery mass.
Round steel and weight force
For a solid round bar, volume = π × diameter² × length ÷ 4. Use the round-tube formula for a hollow section instead. kg is a unit of mass; weight force in N equals mass in kg × 9.80665 for standard Earth gravity.
Dimensions and theoretical material weight
Uses ideal geometry. Density is editable and dimensions are in mm; results are neither manufacturer weighings nor structural checks.
Worked default example
1000 × 500 × 5 mm plate, density 7.85 g/cm³: mass = 1000 × 500 × 5 × 7.85 ÷ 1,000,000 kg. Result: 19.625 kg.
Reference nominal densities, not grade certification
| Material | g/cm³ | kg/m³ |
|---|---|---|
| Carbon steel | 7.85 g/cm³ | 7,850 kg/m³ |
| 304 stainless steel | 7.93 g/cm³ | 7,930 kg/m³ |
| 6061 aluminium | 2.7 g/cm³ | 2,700 kg/m³ |
| Copper | 8.96 g/cm³ | 8,960 kg/m³ |
Source: sumhut built-in material models. These are estimating assumptions, not a published engineering standard or manufacturer guarantee; actual grade, temperature, composition and tolerances may differ.
Choose existing specifications in the original object calculator
Sources and further reading
Calculation basis: solid material geometry × material density, using this site’s reference models. Procurement, lifting, structural capacity, pressure rating and engineering compliance require separate verification.