Foundry & Forging calculator

Gating Ratio Calculator

Calculate a gating ratio from sprue, runner, and ingate area or another approved gating-system basis. Use it when a casting engineer or patternmaker checks whether a gating layout matches the intended pressurized or non-pressurized gating practice.

What this calculator does

  • Calculate a gating ratio from sprue, runner, and ingate area or another approved gating-system basis.
  • Use it when a casting engineer or patternmaker checks whether a gating layout matches the intended pressurized or non-pressurized gating practice.
  • Compares gating-section areas for a casting layout.

Formula used

  • Gating Ratio Calculator ratio = upstream gating area ÷ downstream ingate area
  • Converted gating ratio calculator ratio = ratio × reporting conversion multiplier

Inputs explained

  • Upstream gating area: Enter sprue base area, runner area, or the selected upstream gating section.
  • Downstream ingate area: Enter total ingate area or the downstream gating section being compared.
  • Reporting conversion multiplier: Use 1 unless converting to a normalized or shop-standard reporting basis.

How to use the result

  • Use during pattern and gating review.
  • This calculator is an estimating tool. Results can change with alloy chemistry, furnace practice, ladle losses, mold design, gating and riser layout, core condition, pattern allowance, die temperature, press condition, inspection criteria, rework rules, energy rates, labor standards, and actual shop performance. Validate safety-critical, metallurgical, tooling, press-capacity, and customer-spec decisions with qualified engineering, metallurgy, OEM data, and the applicable control plan.

Common questions

  • What information do I need before using the Gating Ratio Calculator? Use matched sprue, runner, or ingate areas from the same gating layout.
  • What does the result mean? It reports the gating area ratio and converted ratio if a shop multiplier is used.
  • When is the result only an estimate? This calculator is an estimating tool. Results can change with alloy chemistry, furnace practice, ladle losses, mold design, gating and riser layout, core condition, pattern allowance, die temperature, press condition, inspection criteria, rework rules, energy rates, labor standards, and actual shop performance. Validate safety-critical, metallurgical, tooling, press-capacity, and customer-spec decisions with qualified engineering, metallurgy, OEM data, and the applicable control plan.
  • What decision can I make from the result? Use it to compare gating designs, document pattern changes, or troubleshoot turbulence, misruns, and inclusions.

Last reviewed 2026-05-12.