The engineering question
Solid density connects finished-part volume to mass. Melt density belongs to a stated molten processing condition when comparing shot mass with injection-unit volume. Filled grades, moisture, temperature, and test basis matter.
What to document
Do not transfer a material-hub solid-density example into a melt-volume calculation without a documented melt-density basis.
Practical workflow
Use Resin Weight for finished-part mass and Shot Volume for a documented melt-density conversion.
Validation boundary
Use manufacturer documentation, grade-specific supplier data, controlled process records, and trials for any equipment, quality, material, or commercial commitment. A static calculator is a transparent starting point, not a simulation or approval.