Building Materials Manufacturing worked example

Glass Cullet Ratio with cullet charged to the glass batch of 18 tons: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop cullet charged to the glass batch to 18 tons, then walk the calculation through step by step. Calculate cullet percentage in a glass batch from cullet tons and total batch tons.

The inputs for this scenario

  • Cullet charged to the glass batch: 18 tons (the input this scenario stresses; the baseline uses 35)
  • Total glass batch charge: 100 tons (held at the documented default)
  • Percent conversion multiplier: 100 x (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Raw glass cullet ratio = cullet charged to the glass batch ÷ total glass batch charge.
  • Glass Cullet Ratio works out to 18 % cullet at these inputs, and this is the headline figure for the scenario.
  • Raw glass cullet ratio works out to 0.18 value at these inputs.
  • Percent conversion multiplier works out to 100 x at these inputs.
  • Total glass batch charge works out to 100 value at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where cullet charged to the glass batch sits at 35 tons and the headline result is 35 % cullet, this scenario comes in 48.57% below the baseline at 18 % cullet.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to cullet charged to the glass batch, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It reports the charged ratio by weight only — it does not account for cullet contamination, color mismatch, or moisture, which determine how much cullet you can actually run.

Results at a glance

  • Glass Cullet Ratio: 18 % cullet (headline result)
  • Raw glass cullet ratio: 0.18 value
  • Percent conversion multiplier: 100 x
  • Total glass batch charge: 100 value

Run it with your numbers

  • To rerun this with your own numbers, open the live Glass Cullet Ratio calculator, set cullet charged to the glass batch to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.