Water, Wastewater & Pump Systems Manufacturing worked example

Impeller Machining Cost at 72% share needing full machining: a worked example

This worked example runs the impeller machining cost numbers for a tougher week than the baseline: 72% share needing full machining instead of the typical 100%. Estimate impeller machining cost for water and wastewater pumps from batch size, per-part machining cost, the share needing full machining, and fixed setup adders.

The inputs for this scenario

  • Impellers to machine: 120 impellers (held at the documented default)
  • Machining cost per impeller: 85 $ / impeller (held at the documented default)
  • Share needing full machining: 72 % (the input this scenario stresses; the baseline uses 100)
  • Fixed setup and fixturing cost: 1,800 $ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Total machining cost = impellers to machine x machining cost per impeller x share needing full machining + fixed setup and fixturing cost.
  • Total impeller machining cost works out to 9,144 $ at these inputs, and this is the headline figure for the scenario.
  • Impeller machining cost per unit works out to 76.2 $ / piece at these inputs.
  • Variable impeller machining cost works out to 7,344 $ at these inputs.
  • Fixed impeller machining cost adder works out to 1,800 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where share needing full machining sits at 100% and the headline result is 12,000 $, this scenario comes in 23.8% below the baseline at 9,144 $.
  • Use it when quoting an impeller machining job or choosing a batch size that spreads fixturing cost effectively. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Total impeller machining cost: 9,144 $ (headline result)
  • Impeller machining cost per unit: 76.2 $ / piece
  • Variable impeller machining cost: 7,344 $
  • Fixed impeller machining cost adder: 1,800 $

Run it with your numbers

  • To rerun this with your own numbers, open the live Impeller Machining Cost calculator, set share needing full machining to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.