Injection Molding Cost: Price Per Part, Tooling and TCO

How Much Does Injection Molding Cost?

Think about it in three layers:

• Tooling cost (one-time). Paid up front. It sets long-term stability: cycle time, scrap rate, maintenance and mold life.
• Part cost (recurring). Paid on every run. As volume grows, it usually becomes the biggest share of total spend.
• TCO (what really matters). TCO = tooling + part cost × volume + downtime + scrap + engineering change risk.

Four things raise total cost fastest once production starts:

1. Cycle time drift. A cycle time that looks fine at trial can creep up in production through cooling imbalance, ejection issues or an unstable process window. Small increases get expensive at scale.
2. Scrap and rework.Defects rarely show in the quote. They waste resin, press time, labor and inspection, and they delay deliveries.
3. Oversized press tonnage. Poor gating or layout can force a bigger press, which raises the hourly rate.
4. Maintenance downtime. Low-grade steel, weak heat treatment or overly complex actions mean more stoppages.

Buyer takeaway: if two suppliers quote similar part prices but one can prove stable cycle time, low scrap and predictable maintenance, that supplier usually delivers the lower TCO, even with a higher tooling price.

Get an Injection Molding Cost Estimate

Enter your part and volume below for a quick estimate. Treat it as a planning number. A firm quote needs your 3D file.

How to Calculate Injection Molding Cost Per Part

Injection molding cost per part (also called cost per unit or piece price) is built from five pieces:

Resin + Press time + Scrap allowance + Amortized tooling + Packing / secondary ops

• Resin = (part weight + runner share) × resin price per kg.
• Press time = (cycle time ÷ cavities) × press hourly rate.
• Scrap allowance = (resin + press time) ÷ (1 − scrap rate), minus the original.
• Amortized tooling = mold price ÷ parts you expect to make on it.
• Packing and secondary ops = assembly, printing, bagging, labels.

Worked example: injection molding cost breakdown

Illustrative inputs, not our rates. Swap in your own numbers: a 40 g ABS housing, 2-cavity cold-runner tool (8 g runner per shot), ABS at $2.00/kg, 30-second cycle, press at $20/hour, 2% scrap, a $12,000 mold amortized over 100,000 parts, and $0.01 packing.

Notice the tooling line. At 100,000 parts it is the biggest single cost. Spread the same mold over 1,000,000 parts and it drops to $0.012, taking the total to about $0.197. That is why volume decides the mold, and the mold decides the part price.

Want to run your own numbers? Use our piece-price calculator and cycle time calculator.

Plastic Injection Molding Cost Per Part: Key Drivers

Part cost is recurring. Over a program’s life it often exceeds the mold price, and small inefficiencies compound with every shot.

• Material type and weight. Resin price, density and part weight set the material line. Cutting wall thickness or removing excess mass lowers it for the whole program.
• Cycle time. It sets how many parts a press makes per hour. One or two extra seconds add up fast over hundreds of thousands of shots.
• Press size. Bigger presses cost more per hour. A poor layout can force an oversized press without adding any value.
• Labor and automation. Manual loading, trimming or inspection adds cost and variation. Automation lowers unit cost at scale, but needs planning up front.
• Scrap rate. Unstable processing, poor cooling or uneven ejection create rejects. Scrap is an invisible cost that compounds at volume.
• Cavity count. More cavities divide press time across more parts. The mold costs more, but each part costs less.

Critical insight: a cheaper mold can cut tooling cost, but if it brings longer cycles, more scrap or unstable runs, it makes more expensive parts for years.

Tooling Cost in Brief

Mold cost is a one-time investment, typically $1,500–80,000 depending on part size, cavity count, steel and side actions. It is paid once, but it sets your cycle time, scrap rate and maintenance for the life of the program. A lower tooling quote often hides lighter steel, weaker cooling or skipped validation. For price bands, a cost breakdown and a free estimator, read our full injection mold cost guide.

Total Cost of Ownership (TCO) in Injection Molding

Judging on tooling price or part price alone is misleading. The real number is TCO: the total cost of producing the part over its whole life.

Here is the same worked example, compared across two suppliers at 1,000,000 parts:

Supplier A looks $2,000 cheaper on day one. Two extra seconds and one extra point of scrap cost about $5,500 more over the run. Supplier B wins, and the gap grows with volume.

What TCO includes

• Tooling cost: mold design, steel, machining and validation.
• Recurring part cost: resin, cycle time, press rate, labor and scrap on every run.
• Operational losses: downtime, rework, process tweaks and frequent maintenance.
• Risk: late deliveries, quality swings and supply interruptions that never show in a quote.

Why TCO matters more than unit price

A mold that costs a little more up front often gives a shorter, steadier cycle, lower scrap, a smaller press and predictable long-term cost. A cheap mold without proper cooling, steel or validation can inflate cost year after year. The cheapest quote rarely produces the lowest total cost.

How to Compare Supplier Quotes Using TCO

Do not ask “who is cheapest?”. Ask “who is most predictable?“. Use this checklist:

• Is cycle time validated with a trial report, a stable window and balanced cooling?
• What scrap rate is expected in mass production?
• What mold life, in shots, is the tool built for?
• What validation is included: samples, dimensional reports, PPAP-style documents?
• What are the maintenance plan, spare parts, lead times and warranty scope?

Tip: if a supplier cannot explain cycle time, scrap rate and mold life clearly, the quote is incomplete.

Hidden Costs in Injection Molding Most Buyers Miss

Many quotes look competitive until production starts. These hidden costs rarely appear in the first quotation, yet they push TCO up over time.

How to reduce hidden costs

You rarely remove hidden costs by negotiating. You remove them with proper mold design and steel choice, validated cycle times, clear mold life and maintenance terms, and open communication with the supplier. The most expensive programs are not the ones with high tooling cost. They are the ones with uncontrolled variables.

China Injection Molding Cost: Landed, Not Ex-Works

A China quote is usually ex-works or FOB. Your real part cost is landed: part price plus freight, insurance, duty, broker and port fees. On light, high-value parts, freight is small. On bulky, low-value parts, it can rival the part price itself.

• Check the correct HS code. Molds and molded parts are classified differently; see HS 8480.71 vs 3926.90.
• Duty and extra tariffs change. Check current rates with your customs broker before you compare suppliers.
• Model it with the landed-cost tool on our interactive molding tools page.
• For the wider picture, read how to manage costs when buying from China.

For a full worked example with freight, duty and inspection added line by line, see buying injection molding from China: landed cost and terms.

Injection Molding Cost Reduction Ideas

Most part-cost savings come from design and process, not from squeezing the supplier.

• Cut cycle time. Cooling is usually the biggest share of the cycle. Thinner, uniform walls and well-placed cooling lines shorten it.
• Choose resin strategically. Pick the cheapest grade that meets the spec. Ask whether regrind or recycled content is acceptable.
• Use fillers where strength is not critical. Mineral fillers such as calcium carbonate or talc can cut material cost and add stiffness.
• Right-size cavities. More cavities spread press time over more parts. Match the count to your real annual volume.
• Automate repetitive steps. Robot take-out, auto-degating and in-line inspection cut labor and variation.
• Simplify the part. Fewer undercuts mean fewer actions, shorter cycles and less maintenance.
• Drive scrap down. A validated process window and early defect detection protect every lot.
• Use soft tooling for short runs. Below about 1,000 parts, an aluminum or bridge tool is often cheaper overall. See low volume injection molding.

For a deep dive, read our guide to reducing total part cost.

What We Need for an Accurate Injection Molding Quote

A reliable quote needs more than a part size or a photo. These inputs let us estimate tooling, cycle time, scrap risk and stability, so you can compare suppliers on TCO. See also how we prepare a quotation.

• 3D file (STEP or IGES) plus a 2D drawing. Show critical dimensions, datums and functional fits. A marked-up PDF works if you have no full drawing yet.
• Material, color and additives. GF, FR rating, UV. Share a preferred brand and grade if you have one, such as SABIC, DuPont or RTP Company.
• Annual volume and program life. These set cavity count, steel, hot runner and automation choices.
• Tolerance zones and cosmetic faces. Mark where appearance matters and where it does not.
• Assembly needs. Inserts, welding, screws, heat staking or other post-molding steps.
• Packaging, labeling and inspection standards. FAI, CPK targets or PPAP-style reports, stated up front.

Optional but useful: target delivery date, sample quantity, existing part or mold problems, and the operating environment (heat, UV, chemicals). Check MOQ and lead time logic before you set a schedule.

Cost Hub Reading Map

Use this map to go deeper. A-level pages build your cost model, B-level pages explain why quotes differ, and C-level covers China sourcing.

Frequently Asked Questions