polystyrene rod weight calculator
Enter the dimensions of a polystyrene rod and this works out its volume and weight. Solid general-purpose polystyrene, not the expanded foam.
- Weight of one rod
- 0.515 418
- Volume of one piece
- 490.874
- Weight per metre of length
- 0.515 418 kg/m
- Density used
- 1050 kg/m3
Show the working
- Diameter = 25
- Length = 1000
- Number of pieces = 1
- volume_mm3 = pi * (25/2)^2 * 1000 = 490 874
- Volume of one piece = 490 874 / 1000 = 490.874
- Density used = 1050 = 1050
- Weight of one rod = 490 874 * 1050 / 1e9 = 0.515 418
- Total weight = 0.515 418 * 1 = 0.515 418
- Weight per metre of length = 490 874 / 1000 * 1000 * 1050 / 1e9 = 0.515 418
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
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The formula
- Volume = pi x (diameter / 2)^2 x length
- Weight = volume x density, with density = 1050 kg/m3
- One cubic millimetre of a material at 1000 kg/m3 weighs exactly one milligram, so the millimetre-to-kilogram step is a shift of the decimal point rather than a rounded factor.
Solid general-purpose polystyrene, not the expanded foam.
Dimensions are nominal. Mill tolerances on thickness, and the corner radii on formed sections, both move the real weight by a percent or two.
Every field takes inches or feet as readily as millimetres: change the unit next to it and the conversion is done exactly before the arithmetic starts.
Frequently asked
What is the density of polystyrene?
1050 kg/m3, which is 1.050 g/cm3. Solid general-purpose polystyrene, not the expanded foam.
How do you calculate the weight of a polystyrene rod?
Volume = pi x (diameter / 2)^2 x length. Multiply the volume by the density of polystyrene, 1050 kg/m3, taking care that both are in the same unit system.
Can I enter dimensions in inches?
Yes. Each dimension field has its own unit selector, and inch, foot, millimetre, centimetre and metre entries are all converted exactly before anything is multiplied.
Where the numbers come from
- Densities are nominal room-temperature values for the grade named, drawn from the usual mill and handbook figures.