How do you calculate good capacity in a ramp?

Multiply output per cycle by available cycles to get gross capacity, then multiply by uptime and first-pass yield. With 4 units/cycle over 480 cycles at 90% uptime and 97% yield, that is 1,920 x 0.90 x 0.97 = 1,676 good units.

What is the gross capacity in the example?

1,920 units, 4 magnets per sinter cycle across 480 available cycles, before any losses. Good capacity of 1,676 is what survives after downtime and yield deductions.

How much do I lose to downtime versus yield?

In the example, downtime removes 192 units and first-pass yield removes another 51.8 units. Downtime is the bigger loss here, so improving availability returns more units than chasing yield.

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

Mature NdFeB lines often run 95-98% first-pass; early ramp can be well below that. The example's 97% is a healthy near-steady-state number, not a launch-day figure.

Why not just quote gross capacity?

Because you cannot ship magnets that failed inspection or the cycles a down furnace never ran. Quoting 1,920 instead of 1,676 overcommits by roughly 14% and risks a missed launch.

How do I use this as the line matures?

Raise the uptime and yield inputs as your data improves and re-run it. Each point of uptime or yield adds units directly proportional to gross capacity.

Rare Earth Magnet & Motor Materials calculator

Production Ramp Planner Calculator

The production ramp planner turns raw press-and-sinter throughput into the number of good, saleable rare earth magnets you can actually promise during a ramp, after discounting for equipment uptime and first-pass yield. Operations planners and program managers launching a new motor-magnet program use it to set realistic commitments before the line has stabilized. It matters because early-ramp NdFeB lines rarely hit nameplate: furnaces need conditioning, coating baths drift, and yield climbs slowly, so gross capacity badly overstates deliverable units. By separating downtime loss from yield loss, the planner shows which lever, availability or quality, is costing you the most units.

What this calculator does

Estimate production ramp planner 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 production ramp planner 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 converts output per cycle and available cycles into good units after applying expected uptime and first-pass yield.

Formula used

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

Inputs explained

Magnets pressed per sinter cycle:
Sinter cycles available in the plan window:
Expected equipment uptime:
Expected first-pass yield:

How to use the result

Use it during a new-line or new-product ramp to set deliverable commitments before the process is fully mature.
It assumes uptime and yield are independent and stable across the window; real ramps improve week over week, so re-run it as the numbers move.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 542.853 (BLS, Jul 2026), up 52.8% 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).
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 capacity in a ramp? Multiply output per cycle by available cycles to get gross capacity, then multiply by uptime and first-pass yield. With 4 units/cycle over 480 cycles at 90% uptime and 97% yield, that is 1,920 x 0.90 x 0.97 = 1,676 good units.
What is the gross capacity in the example? 1,920 units, 4 magnets per sinter cycle across 480 available cycles, before any losses. Good capacity of 1,676 is what survives after downtime and yield deductions.
How much do I lose to downtime versus yield? In the example, downtime removes 192 units and first-pass yield removes another 51.8 units. Downtime is the bigger loss here, so improving availability returns more units than chasing yield.
What is a good first-pass yield for sintered magnets? Mature NdFeB lines often run 95-98% first-pass; early ramp can be well below that. The example's 97% is a healthy near-steady-state number, not a launch-day figure.
Why not just quote gross capacity? Because you cannot ship magnets that failed inspection or the cycles a down furnace never ran. Quoting 1,920 instead of 1,676 overcommits by roughly 14% and risks a missed launch.

Last reviewed 2026-07-13.