Foam Toy Density and Weight Calculator
Calculate the weight and firmness of EVA foam, soft polyurethane, and high-density polyurethane for toy making.
Enter dimensions and foam type to get weight in grams.
Foam toys and foam components (helmets, bath toys, foam swords, floor mats) vary widely in weight and firmness depending on foam type and density.
The formula:
weight_g = volume_cm3 x density_g_per_cm3
Common toy foams and their densities:
- EVA foam (craft foam sheets, cosplay, bath toys): 45-50 kg/m3 = 0.045-0.050 g/cm3. Closed-cell, waterproof, very lightweight, easy to cut.
- Soft polyurethane foam (foam inserts, stuffed character bases): 20-30 kg/m3 = 0.020-0.030 g/cm3. Open-cell, compressible, used for squeezy toys.
- High-density polyurethane (HD poly, rigid toy components): 60-80 kg/m3 = 0.060-0.080 g/cm3. Holds shape under load, carveable.
Volume calculation for common shapes:
- Rectangular block: L x W x H (in cm)
- Cylinder: pi x r squared x H
- Sphere: (4/3) x pi x r cubed
For irregular shapes, use the water displacement method: fill a graduated container with water, submerge the foam (weigh it down if needed), and measure displacement in mL — that is the volume in cm3.
Safety note: EVA foam for children’s toys should be certified free of formamide (a residual from manufacturing). Look for REACH compliance or formamide test reports when purchasing foam for children’s products.