Plastic Properties and Weight

These pages answer questions about the material itself. Calculate the weight of a plastic part from its shape, look up density, Shore hardness, recycling symbols and film or sheet thickness, or check the weight of an acrylic sheet.

Tools in this group

• Plexiglass Thickness Chart — Pick a sheet thickness and enter its length and width to see the weight, with every common acrylic thickness in inches and mm.
• Foam Density Chart: EPS, XPS, Spray and Memory Foam — Type a foam density in lb/ft³, kg/m³ or g/cm³ to convert it and see which foam types it matches. The full chart is below.
• Mil to mm Converter and Thickness Chart — Convert film and sheet thickness between mil, inches, millimetres, microns and gauge, or read it off the chart.
• Plastic Density Chart (Density of HDPE, PP, PLA) — Typical densities of common plastics in every unit, with specific gravity and whether each one floats in water.
• Plastic Melting Point Chart — Pick a plastic and type a temperature to see its melting range, glass transition and whether it is glassy, soft, melting or molten.
• Plastic Weight Calculator — Choose a shape and a plastic, enter the dimensions and get the weight per piece, per length and for the whole order.
• Polyethylene vs Polypropylene Comparison — Compare HDPE, LDPE and polypropylene on melting range, density, recycling code, strength, chemical resistance and typical uses.
• Recycling Symbols Chart (Plastic Codes 1–7) — Pick a number or type an abbreviation to see which plastic a resin identification code stands for and where it is used.
• Shore Hardness Chart: Shore 00, A and D Durometer Scales — Enter a durometer reading to see where it sits among everyday items, its rough equivalent on the other scale and an approximate modulus.
• Types of Plastic: Groups, Codes and Uses — Filter 23 plastics by group, thermoplastic or thermoset, or search by name or use to see its recycling code and typical products.