Why does the per-part cost fall as the batch grows?

Only the wear consumption scales with batch size. The setup and crib adders stay flat, so a longer batch spreads them across more parts and lowers the per-part figure.

Which costs belong in the fixed adders?

Setup and tool presetting for the batch, plus tool crib labor and its overhead. Material, machine time, and the cutting edges themselves sit elsewhere in the quote.

Should I use the total or the per-part figure?

Use the total to plan the tooling budget for the batch. Use the per-part figure to compare jobs of different sizes on one basis or to feed a part cost model.

How do I find the wear cost per part?

Track edge changes over a run and divide the cost of those edges by the parts they produced. A short trial batch with a fresh edge gives a defensible first figure.

CNC Machining calculator

Tool Wear Cost Calculator

Price the cutting edges a batch consumes and the fixed tooling adders it carries. The per-part figure falls as the batch grows because the fixed adders do not scale.

What this calculator does

Total tool wear cost for a batch, its per-part share, and how fixed adders spread across more parts.

Formula used

Batch wear consumption = machined parts in batch × tool wear cost per part
Fixed adders = fixed setup and tool preset cost + tool crib labor and overhead
Total tool wear cost = batch wear consumption + fixed adders
Tool wear cost per part = total tool wear cost ÷ machined parts in batch

Inputs explained

Machined Parts in Batch: Parts machined in the batch that consume tool edges.
Tool Wear Cost per Part: Wear cost each part consumes, from your tooling records.
Fixed Setup and Tool Preset Cost: Setup and tool presetting cost charged to the batch.
Tool Crib Labor and Overhead: Tool crib labor and overhead for the same batch.

How to use the result

Best suited to quoting a batch's tooling cost, testing how batch size moves unit cost, comparing edge grades on one job.
A single average hides hard spots and hard lots that shorten edge life. Excludes tool repair, regrinding, and the cost of scrapped parts.

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

Why does the per-part cost fall as the batch grows? Only the wear consumption scales with batch size. The setup and crib adders stay flat, so a longer batch spreads them across more parts and lowers the per-part figure.
Which costs belong in the fixed adders? Setup and tool presetting for the batch, plus tool crib labor and its overhead. Material, machine time, and the cutting edges themselves sit elsewhere in the quote.
Should I use the total or the per-part figure? Use the total to plan the tooling budget for the batch. Use the per-part figure to compare jobs of different sizes on one basis or to feed a part cost model.
How do I find the wear cost per part? Track edge changes over a run and divide the cost of those edges by the parts they produced. A short trial batch with a fresh edge gives a defensible first figure.

Last reviewed 2026-10-01.