How Much Does a Prototype Cost?

Designing a new product usually means juggling a hard deadline, a target quality level, and a real budget. That’s the lead time–quality/tolerance–cost triangle in action. This guide gives you defensible, 2024–2026-sourced ranges and a practical framework to estimate rapid prototyping cost and choose the right process—CNC machining, vacuum (urethane) casting, or injection molding (prototype/bridge tooling)—without missing your build.

Key takeaways

• Rapid prototyping cost is dominated by setup/programming, machine-hour rates, material class, tolerances, surface finish, geometry/complexity, quantity, and expedite risk.

• For quantity and specification bands common in early builds, a good rule of thumb is: CNC for 1–50/100 units or tight-tolerance metals/plastics; vacuum casting for 10–200 cosmetic plastic-like parts; injection molding when you can amortize a tool and need 500–10k+ units.

• Tightening tolerances and polishing to premium finishes pushes time on machine and inspection up nonlinearly; use ISO 2768 “m” as the default and tighten only where function demands it.

• Aluminum injection molds can start around the low thousands and, for simple designs, first shots can arrive quickly; per-part cost collapses at scale, but only after tooling is paid down.

• Always cite assumptions in your estimate, then request two or three quotes to validate ranges before locking a plan.

What really drives rapid prototyping cost

When engineers ask “how much does a prototype cost,” the honest answer is “it depends”—and here’s what it depends on.

• Setup/programming and fixturing: One-offs carry most of their cost here; unit price drops as you spread this across more parts.

• Machine-hour rate by class: 3‑axis vs. 5‑axis rates differ significantly; complex parts that need multi‑axis time cost more per hour of runtime. 

• Material and machinability: 6061 aluminum cuts faster than hardened steels; resin choice in casting or molding changes cure/cycle time and scrap risk.

• Tolerance band and inspection plan: Moving from general ISO 2768‑m to fine bands increases cycle time, measurement steps (CMM), and potential scrap.

• Surface finish: Mirror polishes or tight Ra targets add passes and hand work; in molding, SPI A finishes require significant polishing. 

• Geometry and complexity: Deep pockets, thin walls, undercuts, and freeform surfaces raise programming time, tool changes, and setups.

• Quantity and lead time: More parts amortize fixed cost; rush paths may require premium capacity or design compromises.

Two practical levers move cost fastest: keep non‑critical dimensions at ISO 2768‑m and avoid premium finishes unless they are functional. Think of it this way: every tighter digit on a print is a request for slower feeds, more inspection, and a higher chance of rework.

Tolerance/finish cost‑pressure quick map

Rapid prototyping cost by process: CNC vs vacuum casting vs injection molding

CNC machining: When precision or metals lead

Hourly rates vary by machine class and region. Typical ranges compiled in 2024–2026 content place 3‑axis around ~$60–$80/hour within a wider $35–$200/hour band, while 5‑axis often runs ~$120–$200/hour due to complexity and equipment costs. 

How this translates to parts: a simple 1‑off bracket that needs an hour of setup and 1–2 hours on a 3‑axis mill may land in the low hundreds; add tight tolerances, multiple setups, or 5‑axis time and you’re quickly in the high hundreds or beyond. Unit pricing drops fast at 10–100 pieces as you amortize setup.

Cost‑down tactics that don’t harm function:

• Keep default general tolerances at ISO 2768‑m; call out tighter features only where functional fits require it.

• Consolidate operations to reduce setups; ask if a 3‑axis plus indexing can replace 5‑axis for your geometry.

• Avoid unnecessary mirror finishes; specify Ra targets only where they matter.

Vacuum (urethane) casting: Cosmetic plastics in tens to low hundreds

Vacuum casting produces plastic‑like parts from silicone molds poured around a master pattern. Mold life is limited: dated sources cite around 20–30 shots per silicone mold depending on resin and geometry.

What to expect on cost and timing: upfront mold cost is generally in the “several hundred to low thousands USD” range depending on size and complexity, but public, dated figures vary; treat these as qualitative bands and request quotes for your geometry and resin. Per‑part cost remains higher than injection molding at scale due to hand work and mold wear, but the overall time to first parts is typically fast relative to building an injection mold.

Where vacuum casting shines: realistic cosmetics, integral color, and functional prototypes for 10–200 pieces when the design might still change.

For a deeper comparison as quantities rise, see a neutral discussion like vacuum casting vs. injection molding for low-volume production.

Injection molding (prototype and bridge tooling): Pay a tool, win on volume

Economics: injection molding trades high fixed tooling cost for very low marginal part cost at scale. For speed, aluminum tools are common in prototyping and bridge runs. Aluminum molds can start around the low thousands and, for suitable simple designs, first shots can arrive in “seven days or less.”

Per‑part cost behavior: as you pass into the 1k–10k unit zone, per‑part prices can fall to low single digits depending on resin, cycle time, and tool design illustrates how tooling amortization drives this trend over volume.

When to choose aluminum vs steel: use aluminum for rapid prototype/bridge tooling where volumes are modest and the design may evolve; move to steel when the design is frozen and you need long tool life and stable, very low per‑part cost.

The LQC decision framework you can apply today

The core idea: you can’t minimize lead time, maximize quality/tolerance, and minimize cost simultaneously. You pick two, then manage the third.

Quantity and tolerance breakpoints that usually hold:

• If you need 1–50/100 parts or have tight metal tolerances, CNC machining is generally the most economical and the least risky for hitting spec.

• If you need 10–200 plastic‑like parts with show‑surface options and the design may change, vacuum casting balances speed and fidelity without tooling a hard mold.

• If you need 500–10k+ identical parts and your design is stable, injection molding becomes the low‑cost winner once you amortize the tool.

Quality/tolerance lever: Specify ISO 2768‑m for general features, then explicitly call out the few critical fits that truly require tighter control. Each extra tight feature pushes you toward either higher CNC time, more rigorous molding controls, or both.

Lead time lever: If time is the constraint, consider aluminum molds for molding or loosen non‑critical specs to keep the job on 3‑axis CNC. Expedite options exist on many platforms, but premiums vary by provider and design; check quote portals rather than assuming a fixed percentage.

Cost lever: Simplify geometry (fewer setups/undercuts), pick mainstream materials with good machinability/moldability, and right‑size surface finishes (matte where you can, polish only where you must).

Worked example: find the break‑even between CNC and molding

Scenario: a small ABS enclosure, palm‑sized, with light cosmetic requirements and modest bosses/ribs. 

Quantity target: 1,000 units over six months. 

Tolerance: ISO 2768‑m on most features; a few fits tightened locally.

Assumptions (transparent and adjustable):

• CNC: average realized rate $70/hour on 3‑axis, 0.6 hours runtime + 0.2 hours handling per part at scaled production; setup/programming/fixtures total 8 hours amortized over the batch.

• Vacuum casting: silicone mold life 25 shots per mold; per‑part direct and labor costs $25, recognizing geometry can shift this; mold costs treated qualitatively—quotes required.

• Injection molding (aluminum): assume an aluminum tool in the low‑thousands USD (use a placeholder of $6,000 for math illustration only; actual quotes vary), cycle/handling yields $1.20 per part all‑in variable cost at 1k scale; mirror finishes not required. 

CNC unit estimate at 1,000 units:

• Variable per part ≈ (0.8 hours × $70) = $56.00

• Setup amortization ≈ (8 hours × $70)/1,000 = $0.56

• Estimated unit ≈ $56.56 (clearly too high for 1,000 given runtime; this flags that CNC is viable for tens, not thousands, unless CAM/runtime is dramatically lower). Even if runtime were 0.2 hours/part, you’re at ~$14–$15 before material.

Vacuum casting at 1,000 units:

• Mold life ~25 shots implies ~40 molds; with qualitative per‑mold cost in the hundreds to low thousands, the mold count alone becomes prohibitive. Per‑part $25 baseline would place total well above injection molding at this quantity.

Injection molding at 1,000 units (illustrative math):

• Tooling amortization per unit = $6,000 / 1,000 = $6.00

• Variable per unit ≈ $1.20

• Estimated unit ≈ $7.20 (plus shipping/QA). If the actual tool is $10,000, amortization is $10.00, giving ~$11.20/unit—still often better than CNC at true 1,000‑piece scale.

Takeaway: At 1,000 pieces of a plastic enclosure, injection molding with an aluminum tool is usually the economic choice, provided the design is stable enough to warrant the tool. CNC is most competitive in the tens; vacuum casting fits tens to low hundreds where cosmetics matter and design may change.

Practical workflow to get a defensible estimate in hours

Start from your print, not a hunch. First, bracket tolerances: default to ISO 2768‑m and mark only truly critical fits as tight. Next, simplify geometry where possible—eliminate undercuts, increase radii, and specify matte textures on non‑show faces. Then, create a quick estimation sheet: list setup hours, runtime by machine class, and finishing passes for a CNC route; list mold count, resin choice, and labor for a vacuum‑casting route; list tooling type (aluminum vs steel), gating, expected cycle time, and secondary ops for a molding route. With those assumptions captured, request two or three quotes for validation.

A neutral example: you can send the same CAD and tolerance notes to a multi‑process provider to cross‑check your assumptions across processes. For instance, a provider that offers CNC, vacuum casting, and injection molding can sanity‑check whether your quantity and tolerance band makes more sense in CNC or molding, and whether a bridge aluminum tool would pay back. Disclosure: Kaierwo is our product; you can learn more about their capabilities on the Kaierwo homepage.

Once you receive quotes, compare apples to apples: include shipping, inspection documentation, and any expedite charges; note that advertised fast‑turn options exist , but premiums vary and should be confirmed at quoting.

FAQs engineers ask about rapid prototyping cost

Q:How many times should I use the phrase “rapid prototyping cost” in my spec or RFQ? 

A:You don’t need to stuff it anywhere—what matters is clarity. In your RFQ, focus on quantity, material, tolerance band, finish, and the date you need first articles. The keyword is for search; your vendor needs unambiguous numbers.

Q:Is 5‑axis always more expensive than 3‑axis? 

A:The hourly rate usually is, but the total job cost can fall if 5‑axis eliminates multiple setups. The choice is about total cycle time and accuracy risk, not rate alone. 

Q:Can vacuum casting hit tight tolerances? 

A:You can achieve good cosmetic fidelity and functional tolerances on many features, but if you need near‑precision fits across the part, CNC or a well‑tuned injection mold is more reliable. Mold life of 20–30 shots also limits scale.

Q:When does aluminum tooling stop making sense? 

A:When volumes are high enough or resins/part geometries demand durability, steel tooling wins on life and process stability.