Why divide by the usable share instead of multiplying?

A share below 100% means more magnets must be bought to install the required count. Dividing installed magnets by the share gives the purchased count, while multiplying would shrink the order as scrap rises.

Is the usable share the same as first-pass yield?

Use magnet-specific inspection and handling data. A whole-motor first-pass yield includes operations that never touch the magnets, so it understates magnet loss.

Does the fixed program cost change with volume?

No. It is charged once per motor in this per-motor model, so the per-magnet figure falls as more magnets are installed. Remove it if you want the variable magnet cost alone.

What if a supplier ships extra magnets for scrap?

Keep the installed count as what the motor needs and let the usable share absorb the loss. If the supplier ships spares, reconcile the delivered quantity with the share so the purchased count matches your purchase order.

Motors, Generators & Electrification Equipment calculator

Magnet Cost per Motor Calculator

Price the magnets in one motor with a purchased count that honors the usable share. A share below 100% means buying more magnets than the motor installs, so the cost per motor rises as yield falls.

What this calculator does

Magnet cost per motor from installed magnets, delivered magnet price, usable share and fixed program cost.

Formula used

Magnets purchased per motor = installed magnets ÷ (usable share ÷ 100)
Variable cost = purchased magnets × delivered cost per magnet
Total cost per motor = variable cost + fixed program cost
Cost per installed magnet = total cost ÷ installed magnets

Inputs explained

Installed Magnets per Motor: Whole magnets installed in one motor on the build list.
Delivered Cost per Magnet: Delivered price per magnet, freight and tariffs included.
Usable Magnet Share: Share of delivered magnets that survive to installation.
Fixed Magnet Program Cost: Fixed program cost charged to each motor in the run.

How to use the result

Best suited to quoting a motor with rare-earth magnets, charging magnet scrap to a motor program, comparing two magnet suppliers.
A single average share hides scrap that varies by magnet grade or vendor. The fixed program cost is spread over each motor, not amortized across a year.

Current U.S. benchmarks

The producer price index for primary nonferrous metals (a broad metals benchmark, not copper alone) stands at 544.731 (BLS, Aug 2026), up 49.3% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,543 per tonne (IMF via FRED, Jul 2026).
Steel mill PPI stands at 381.162 (BLS, Aug 2026), up 23.4% from a year earlier. New factory orders are up 8.5% year over year (Census).
The U.S. has 5,397 electrical equipment and appliances establishments employing about 369,437 workers (Census County Business Patterns, 2023).

Common questions

Why divide by the usable share instead of multiplying? A share below 100% means more magnets must be bought to install the required count. Dividing installed magnets by the share gives the purchased count, while multiplying would shrink the order as scrap rises.
Is the usable share the same as first-pass yield? Use magnet-specific inspection and handling data. A whole-motor first-pass yield includes operations that never touch the magnets, so it understates magnet loss.
Does the fixed program cost change with volume? No. It is charged once per motor in this per-motor model, so the per-magnet figure falls as more magnets are installed. Remove it if you want the variable magnet cost alone.
What if a supplier ships extra magnets for scrap? Keep the installed count as what the motor needs and let the usable share absorb the loss. If the supplier ships spares, reconcile the delivered quantity with the share so the purchased count matches your purchase order.

Last reviewed 2026-10-01.