Metal bar weight calculator
Mass of round, square and flat bar from the section size and length.
Fill in the fields and the result will appear here automatically.
Calculates mass of solid round, square or rectangular bar from section area, length and manually supplied density. It also shows mass per metre and metres per tonne. This is a geometric estimate; material grade, dimensional tolerances, coatings and transport or lifting conditions are not determined.
How it works
Formula and logic
S=πa²/4 for round, S=a² for square and S=a·b for flat bar; S is in mm². Volume=S·L/10⁶ in m³; mass=S·L·ρ/1000 in kg for L in m and ρ in g/cm³. Mass per metre=S·ρ/1000; metres per tonne=1000/mass per metre. Active dimensions, length and density are positive and finite; b is used only for flat bar.
Example
A steel round bar 20 mm across and 6 m long weighs 14.797 kg — 2.466 kg per metre. Assumed density: 7.85 g/cm³.
Fields and units
- Cross-section — list option
- Diameter or side — mm
- Second side of the flat bar — mm
- Length — m
- Density — g/cm³
How to use
- — Choose round, square or flat bar.
- — Enter section dimensions in mm and length in m; a second side is needed only for flat bar.
- — Enter density manually in g/cm³, not kg/m³.
Method and limitations
- Calculation method
- Formula and logic
- Limitation
- This is a geometric estimate; material grade, dimensional tolerances, coatings and transport or lifting conditions are not determined.
FAQ
Why is density entered manually?
Use a value for the actual material and conditions. There is no grade selector or automatic density table.
What does 7.85 mean?
It is the example density in g/cm³, equivalent to 7850 kg/m³. It does not establish the density of every steel; replace it with actual material data.
Does this support tube or angle?
No. Three solid sections are supported. An angle is not necessarily hollow; its L-shaped geometry is simply absent here. A separate calculator handles round pipe.
Why may actual mass differ?
Actual dimensions, density and coatings may differ from inputs. No universal difference percentage or transport or lifting suitability is established.