What is the difference between uptime and yield?

Uptime is machine availability: the share of planned cycles the machine actually runs. First-pass yield is quality: the share of parts that come off good without rework. Stopped time removes whole cycles, while yield removes individual parts from the cycles that ran.

Why is good capacity below gross capacity?

Two losses sit between them. Downtime removes the cycles the machine never started, and first-pass yield removes the parts scrapped or sent to rework from the cycles that did run. The two loss rows keep those effects separate.

How do I raise batch capacity fastest?

Compare the two loss rows. If downtime loss dwarfs scrap loss, improve availability with tool-life management, lights-out monitoring, or faster changeovers. If scrap loss leads, work on the process that causes it before adding cycles.

Can I use this for a batch window with no cycles?

No. A window with zero cycles or zero parts per cycle has no population, so the calculator blocks it and returns no results. Enter the cycles the window can actually run.

CNC Machining calculator

CNC Batch Capacity Calculator

Multiply parts per cycle by the cycles in the window, then take out the shares lost to stopped time and to scrap. The headline good count is the number the schedule can promise.

What this calculator does

Estimate good parts from a CNC batch window after uptime and first-pass yield losses.

Formula used

Gross capacity = parts per cycle × available cycles
Downtime loss = gross capacity × (100 − uptime) ÷ 100
Scrap loss = (gross capacity − downtime loss) × (100 − first-pass yield) ÷ 100
Good capacity = gross − downtime loss − scrap loss; yield = good ÷ gross × 100
Gap to target = good capacity − target good parts

Inputs explained

Parts per Cycle: Good parts the fixture yields each machine cycle.
Available Cycles: Machine cycles the batch window can run.
Expected Uptime: Share of planned cycles the machine actually runs.
First-Pass Yield: Share of parts good before any rework.
Target Good Parts: Good parts the batch window is planned to deliver.

How to use the result

Best suited to sizing an overnight or weekend batch, testing an uptime or yield target, comparing machines for the same job.
Scrap found after the window closes sits outside this count. Setup and first-article cycles are not part of the window.

Current U.S. benchmarks

The producer price index for steel mill products stands at 381.162 (BLS, Aug 2026), up 23.4% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 17,154 machine shops establishments employing about 223,303 workers (Census County Business Patterns, 2023).

Common questions

What is the difference between uptime and yield? Uptime is machine availability: the share of planned cycles the machine actually runs. First-pass yield is quality: the share of parts that come off good without rework. Stopped time removes whole cycles, while yield removes individual parts from the cycles that ran.
Why is good capacity below gross capacity? Two losses sit between them. Downtime removes the cycles the machine never started, and first-pass yield removes the parts scrapped or sent to rework from the cycles that did run. The two loss rows keep those effects separate.
How do I raise batch capacity fastest? Compare the two loss rows. If downtime loss dwarfs scrap loss, improve availability with tool-life management, lights-out monitoring, or faster changeovers. If scrap loss leads, work on the process that causes it before adding cycles.
Can I use this for a batch window with no cycles? No. A window with zero cycles or zero parts per cycle has no population, so the calculator blocks it and returns no results. Enter the cycles the window can actually run.

Last reviewed 2026-10-01.