Calculate polystyrene or Styrofoam weight from sheet, cylinder or volume sizes using typical EPS, XPS or solid PS densities, or enter your own density.

Estimate the total weight of one or more equal pieces.

Foam densities are typical values; use your product’s data-sheet density for an exact weight. Solid PS is the PS 158 N/L grade.

Quantity
Blank uses 1 piece.

Polystyrene Weight Formulas

Material mass equals density ร— material volume. The calculator handles rectangular blocks, solid cylinders, known volume and inverse volume from a target mass. The other section formulas below are manual extensions for uniform material with consistent units.

Polystyrene Flat Sheet Weight Formula = L * W * T * d

Polystyrene Round Bar Weight Formula = (ฯ€/4) * D2 * L * d

Polystyrene Square Hollow Tube Weight Formula = [W2-(W-2T)2] * L * d

Polystyrene Round Hollow Tube Weight Formula = (ฯ€/4) * (Do2 – Di2) * L * d

Polystyrene Square Angle Weight Formula = (2*W*T – T2) * L * d

Polystyrene T Bar Weight Formula = (W*T1 + (H-T1)*T2) * L * d

Polystyrene C Channel Weight Formula = (2*W*T1 + (H-2*T1)*T2) * L * d

Variables used in these equations: 

  • L is the length
  • W is the width (or outer width / leg length / flange width, depending on shape)
  • H is the overall height/depth (for T bars and C channels)
  • T is the thickness (sheet thickness, wall thickness, or angle thickness)
  • d is the density
  • D is the diameter (round bar)
  • Do is the outer diameter (round hollow tube)
  • Di is the inner diameter (round hollow tube)
  • T1 is the flange thickness (for T bars and C channels)
  • T2 is the web thickness (for T bars and C channels)

Each dimension has an independent mm, cm, m, inch or foot control. Density accepts kg/mยณ, g/cmยณ or lb/ftยณ; known volume accepts mยณ, liters, cmยณ, ftยณ or inยณ. Changing a unit converts its entered value. Mass mode reports kg, lb or g and multiplies volume per piece by a whole-piece quantity, default one. Inverse mode returns the total volume for the entered total target mass and an equivalent cube side. Foam volume includes its cells: use the finished foamโ€™s apparent density, subtract cutouts and add facings, adhesive or absorbed water separately. Loose-bead bulk density and solid-resin density are not interchangeable with finished foam density.

What is the density of Polystyrene?

The named solid GPPS reference Styrolution PS 158 N/L has typical density 1,040 kg/mยณ (1.04 g/cmยณ), as listed in the INEOS Styrolution grade comparison. Finished EPS foam is much less dense; BASFโ€™s portfolio lists different processing/application density ranges. The calculatorโ€™s EPS 15 and 25 kg/mยณ and XPS 35 kg/mยณ presets are explicit illustrative assumptions, not universal densities or product specifications. Enter the actual supplier density for your finished material.