Injection Molding worked example

Cushion Percentage with cushion amount of 8.75 g: a worked example

Push cushion amount up to 8.75 g and the picture changes. This example computes every intermediate figure at that operating point. Use this to check that the cushion (material left in front of the screw after injection) is within the recommended 5% to 10% of shot size for consistent part quality.

The inputs for this scenario

  • Cushion amount: 8.75 g (raised for this scenario; the documented default is 3.5)
  • Total shot size: 52 g (unchanged)

Working through the calculation

  • Applying the documented formula (Cushion percentage = (Cushion amount / Total shot size) x 100) to the inputs above produces each figure below.
  • At this operating point the engine returns 16.83 % for rate, the number this scenario is built around.
  • At this operating point the engine returns -16.83 points for gap to target.
  • At this operating point the engine returns 8.75 count for affected count.
  • At this operating point the engine returns 52 count for total count.

How this compares with the baseline

  • Against the tool's baseline example, where cushion amount sits at 3.5 g and the headline result is 6.73 %, this scenario comes in 150% above the baseline at 16.83 %.
  • It computes the cushion as a percentage of total shot size by dividing cushion amount by shot size and multiplying by 100. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Rate: 16.83 % (headline result)
  • Gap to target: -16.83 points
  • Affected count: 8.75 count
  • Total count: 52 count

Run it with your numbers

  • Every input above is editable in the live Cushion Percentage calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.