Motors, Generators & Electrification Equipment worked example

Magnet Cost per Motor at 92% usable magnet share after scrap: a worked example

What does the result look like when usable magnet share after scrap reaches 92%? The full calculation is worked below with real intermediate numbers. Use it when magnet cost on a permanent magnet motor or generator is going through a weighted-cost review against the quote.

The inputs for this scenario

  • Permanent magnets per motor: 100 magnets (unchanged)
  • Delivered cost per magnet: 45 $ / magnet (unchanged)
  • Usable magnet share after scrap: 92 % (raised for this scenario; the documented default is 80)
  • Fixed magnet program cost: 250 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Variable magnet cost = magnets per motor × cost per magnet × usable magnet share) to the inputs above produces each figure below.
  • At this operating point the engine returns 4,390 $ for total magnet cost per motor, the number this scenario is built around.
  • At this operating point the engine returns 43.9 $ / piece for magnet cost per magnet.
  • At this operating point the engine returns 4,140 $ for variable magnet cost.
  • At this operating point the engine returns 250 $ for fixed magnet program cost.

How this compares with the baseline

  • Against the tool's baseline example, where usable magnet share after scrap sits at 80% and the headline result is 3,850 $, this scenario comes in 14.03% above the baseline at 4,390 $.
  • A figure at this level is achievable when usable magnet share after scrap is genuinely sustained, not just peaked for a shift. It treats usable share as a flat multiplier on piece price and does not separately model magnetization energy, adhesive, or yield loss that occurs after the magnets are already installed in the rotor.

Results at a glance

  • Total magnet cost per motor: 4,390 $ (headline result)
  • Magnet cost per magnet: 43.9 $ / piece
  • Variable magnet cost: 4,140 $
  • Fixed magnet program cost: 250 $

Run it with your numbers

  • Every input above is editable in the live Magnet Cost per Motor calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.