Shot Volume Calculator

Convert injection molding shot weight to melt volume. This practical tool is an engineering estimate—validate decisions against machine, material, mold, and process data.

Formula and method

Shot volume = shot weight ÷ melt density.

Inputs and units

Enter measured or specified values in the displayed units. Keep units consistent; results are rounded for practical planning. This first release uses the displayed engineering units rather than a unit-switcher.

Worked example

180 g ÷ 0.95 g/cm³ = 189.47 cm³.

Choose the correct density basis

This conversion needs melt density at the relevant material and process condition. A finished-part solid-density value is appropriate for part mass, not for a barrel-volume comparison.

Cross-check the injection unit

Compare the converted volume with the machine injection-unit documentation and actual screw-stroke limits. Keep the resin grade and temperature basis with the calculation so another engineer can repeat it.

When this estimate is not enough

Do not derive exact barrel capacity from a PS shot-weight rating alone. The material basis, screw, and stated machine condition matter.

Interpretation, assumptions, and limitations

This tool provides an estimate for planning and education. It does not replace machine maker limits, material data sheets, mold trials, cavity-pressure data, process validation, or qualified engineering review.

FAQ

Can I use the density table on the Materials page here?

No. That table identifies solid-density references for finished-part mass. This calculator requires a melt-density basis.