Foundry & Forging worked example

Gating Ratio Calculator with sprue choke cross-section of 6 in²: a worked example

Push sprue choke cross-section up to 6 in² and the picture changes. This example computes every intermediate figure at that operating point. Use it when a casting engineer or patternmaker checks whether a gating layout matches the intended pressurized or non-pressurized gating practice.

The inputs for this scenario

  • Sprue choke (upstream) cross-section: 6 in² (raised for this scenario; the documented default is 2.4)
  • Total ingate (downstream) cross-section: 3.6 in² (unchanged)
  • Reporting unit conversion multiplier: 1 x (unchanged)

Working through the calculation

  • Applying the documented formula (Gating Ratio Calculator ratio = upstream gating area ÷ downstream ingate area) to the inputs above produces each figure below.
  • At this operating point the engine returns 1.67 x for gating ratio calculator ratio, the number this scenario is built around.
  • At this operating point the engine returns 1.67 value for raw ratio.
  • At this operating point the engine returns 1 x for conversion factor.
  • At this operating point the engine returns 3.6 value for downstream ingate area.

How this compares with the baseline

  • Against the tool's baseline example, where sprue choke cross-section sits at 2.4 in² and the headline result is 0.67 x, this scenario comes in 150% above the baseline at 1.67 x.
  • It divides upstream gating area by downstream ingate area and applies a reporting multiplier to express the gating system as a single ratio. 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

  • Gating Ratio Calculator ratio: 1.67 x (headline result)
  • Raw ratio: 1.67 value
  • Conversion factor: 1 x
  • Downstream ingate area: 3.6 value

Run it with your numbers

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

Last reviewed 2026-05-12.