How CNC machining cost is estimated

A rough quote for a machined part is built from a handful of line items, each with its own driver. This is the same model cncquoter itself uses (src/lib/cost.ts, if you want to read the actual code) — nothing here is hidden or approximated further for this page.

The six line items

1. Material — priced on the stock block you buy (bounding box plus a machining allowance on every side), not the finished part, using the material's density and price per kilogram.
2. Roughing — time to remove the stock-minus-part volume, driven by the material's rough material-removal rate (a slower-to-cut material like titanium takes far longer per cubic inch removed than aluminum).
3. Finishing — time proportional to the part's surface area, since finishing passes run over the whole exposed surface rather than bulk volume.
4. Setup — fixed time per workholding orientation (fixturing, indicating, zeroing), amortized across the batch quantity. A part that needs to be flipped and re-fixtured more times costs more here.
5. Programming — fixed time to write the toolpath program once, scaled by a geometric complexity multiplier (more surface area relative to volume — thin walls, pockets, ribs — means more programming time), amortized across the batch.
6. Margin — a straight markup on the fully-loaded cost above.

Every quote also carries a ±percent range on top, reflecting how rough a bounding-box/volume takeoff is without a real toolpath simulation — it's not a statistical confidence interval, just an honest "how sure are we" band.

Worked example

Computed live, right now, by cncquoter's own cost model (src/lib/cost.ts's computeQuote) — not a canned number. Inputs: a plain 60 × 40 × 15mm Aluminum 6061 block (no pockets, so the geometry is exact), 10 pieces, 3mm stock allowance per side, 2 estimated setups, and cncquoter's own default shop settings: $95/hr machine rate, 30 min per setup, 20 min baseline programming, 25% margin, ±25% range.

This is one specific example, not an industry average — change the material, size, or quantity and every number moves. Try it with your own file, or see the assumptions behind every material preset on its material page.

Typical ranges, and where they come from

When people ask "what does CNC machining typically cost per hour" or "per part," there's no single honest answer — it depends entirely on the shop, the machine, the region, and the part. What cncquoter can tell you honestly is its own default assumptions, which you're free to disagree with and edit in the settings panel:

• Default machine rate: $95/hr — a typical fully-loaded shop rate used as the default. Set it to your own shop.
• Default margin: 25% markup on cost.
• Default range width: ±25% around the computed price, reflecting the uncertainty of a mesh-only takeoff.
• Per-material stock price and removal rate: see each material page for the exact numbers this tool assumes.

Every one of those is a preset this tool ships with, shown here as-is — not a market statistic, and not something we've benchmarked against other shops.