How do you calculate good magnet capacity?

Multiply output per cycle by available cycles for gross capacity, then multiply by uptime and first-pass yield. Here 4 units/cycle × 480 cycles = 1,920 gross, then × 90% × 97% = about 1,676 good units.

What's the difference between gross and good capacity?

Gross capacity is the perfect-world total — 1,920 units in this example. Good capacity is what survives downtime and scrap, 1,676 units, and that's the number you can safely promise a customer.

How much capacity does downtime cost me?

In this example, dropping from 100% to 90% uptime removes 192 units. That's the downtime loss line, and it's usually the largest single recoverable chunk on a magnet line.

How much capacity does yield loss cost?

At 97% first-pass yield the calculator shows a 51.84-unit yield loss. Chipped, cracked, or out-of-spec magnets after sintering and machining drive this figure.

Should I improve uptime or yield first?

Compare the two loss lines. Here downtime costs 192 units versus 51.84 for yield, so uptime work recovers roughly four times more capacity per point — attack downtime first.

What is a good first-pass yield for sintered magnets?

Mature NdFeB machining lines often run 92-98% first-pass depending on geometry and coating. The 97% used here is strong; the bigger opportunity in this example is the 90% uptime.

Rare Earth Magnet & Motor Materials calculator

Capacity Gap Calculator

The capacity gap calculator translates a magnet line's theoretical output into the good, sellable magnet count you can actually promise after uptime and yield losses. Production planners and operations managers in NdFeB and SmCo plants use it to separate gross furnace capacity from realistic deliverable capacity, so quotes and schedules reflect what leaves the door rather than what the equipment could do in a perfect week. Rare earth magnet processing chains — press, sinter, machine, coat — accumulate losses at every stage, and downtime plus first-pass yield are the two that most quietly erode committed volume. Seeing the gross number, the good number, and the specific downtime and yield losses side by side tells you exactly where recovered capacity would come from.

What this calculator does

Estimate capacity gap for rare earth magnet and motor materials using production-ready inputs so teams can confirm whether capacity can cover demand before committing the schedule.
Use it when capacity gap in rare earth magnet and motor materials is being asked to take on more work and you need to know if there is room.
It computes gross capacity from output per cycle and available cycles, then discounts it by uptime and first-pass yield to give good deliverable units, plus the downtime and yield losses separately.

Formula used

Gross capacity gap capacity = capacity gap output per cycle × available capacity gap cycles
Good capacity gap capacity = gross capacity × expected capacity gap uptime × expected capacity gap first-pass yield

Inputs explained

Finished magnets pressed per sinter cycle:
Sinter cycles available in the period:
Expected furnace and line uptime:
Expected magnet first-pass yield:

How to use the result

Use it when quoting a magnet program, setting a period production commitment, or deciding whether uptime or yield improvement recovers more capacity.
It applies uptime and yield as flat multipliers; if losses are lumpy or interact (a downtime event that also spikes scrap), the split understates the true coupled loss.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).
The U.S. has 5,397 electrical equipment and appliances establishments employing about 369,437 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate good magnet capacity? Multiply output per cycle by available cycles for gross capacity, then multiply by uptime and first-pass yield. Here 4 units/cycle × 480 cycles = 1,920 gross, then × 90% × 97% = about 1,676 good units.
What's the difference between gross and good capacity? Gross capacity is the perfect-world total — 1,920 units in this example. Good capacity is what survives downtime and scrap, 1,676 units, and that's the number you can safely promise a customer.
How much capacity does downtime cost me? In this example, dropping from 100% to 90% uptime removes 192 units. That's the downtime loss line, and it's usually the largest single recoverable chunk on a magnet line.
How much capacity does yield loss cost? At 97% first-pass yield the calculator shows a 51.84-unit yield loss. Chipped, cracked, or out-of-spec magnets after sintering and machining drive this figure.
Should I improve uptime or yield first? Compare the two loss lines. Here downtime costs 192 units versus 51.84 for yield, so uptime work recovers roughly four times more capacity per point — attack downtime first.

Last reviewed 2026-05-12.