Calculate acrylic sheet weight in lb or kg from length, width and thickness in inches or mm, plus round bars, tubes and other plexiglass shapes.

Material density
Typical acrylic (PMMA) is about 0.0426 lb/inยณ (1,179 kg/mยณ); datasheets often list about 1,190 kg/mยณ.

Acrylic Weight Formulas

The following formulas are used to calculate the weight of Acrylic in different shapes.

Acrylic Flat Sheet/Square Bar Weight Formula = L * W * T * d

Acrylic Round Bar Weight Formula = pi * D2/4 * L * d

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

Acrylic Round Hollow Tube Weight Formula = pi * (R2-r2) * L * d

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

Acrylic T bar Weight Formula = (W*T + (H-T)*T) * L * d

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

Variables used in these equations: 

  • L is the length
  • W is the width (or outer width/leg width depending on the shape)
  • H is the height (for the C-channel formula above, H is the inner height)
  • T is the thickness (for the T-bar formula above, the flange and web are assumed to have the same thickness T)
  • d is the density
  • D is the outer diameter
  • R is the outer radius
  • r is the inner radius
  • T1 is the thickness along the width (web thickness for the C-channel)
  • T2 is the thickness along the height (flange thickness for the C-channel)

The calculator converts each selected length unit and density unit automatically. Its internal units are inches and lb/inยณ; results can be pounds or kilograms. Round hollow tube inputs are radii. C-channel inner height is the clear gap between its two flanges.

What is the density of acrylic?

The calculator retains a default acrylic density of 0.0426 lb/inยณ (approximately 1179 kg/mยณ). Grade-specific values differ; typical PMMA datasheets often specify about 1190 kg/mยณ. Use the materialโ€™s datasheet when available.