Cost & Quoting

Thermoforming Cost Estimation: Building a Defensible Part Quote

A cost model for thermoformed and vacuum-formed parts that isolates the five real drivers, shows how scrap and tooling amortization move the number, and where quotes go wrong.

A thermoformed part quote has five buckets: material, machine time, labor, tooling amortization, and overhead plus margin. On thin-gauge packaging, material is usually 50 to 65 percent of cost. On heavy-gauge industrial parts with long cycles, machine time and labor climb to 40 to 55 percent combined. Get the mix right before optimizing: shaving 2 cents of labor on a part where resin is 60 percent of cost is wasted effort. Use the Plastic Sheet Cost calculator to anchor the material line, then layer the other four buckets on top with the drivers below.

Material cost is blank mass times resin price, not part mass, and this is where estimators bleed margin. If your part uses 0.242 lb of blank at $1.35/lb HIPS, that is $0.327 of resin per part before scrap. But you buy the whole blank and sell only the formed part, so the skeleton web is paid material. Quote the full blank, then recover regrind value separately at 30 to 60 percent of virgin price if the resin is reground in-house. The Trim Scrap Percentage and Sheet Usage Per Part calculators give you the blank mass and web fraction the quote depends on.

Scrap is a cost multiplier, not a line item, and it compounds the material number. At 35 percent trim scrap, every $1.00 of net part material actually consumes $1.54 of purchased sheet ($1.00 / (1 - 0.35)). Regrind offsets some of that: if you recover 40 percent of scrap value, effective material cost drops back toward $1.30. Buyers who ignore regrind economics overpay; suppliers who ignore scrap underquote and lose it on the floor. Nail the scrap percent per tool, because a redesign that drops scrap from 40 to 28 percent can cut total part cost 6 to 10 percent.

Machine time is priced as an hourly rate times cycle time divided by cavity count. A heavy-gauge line might carry a burdened rate of $85 to $160/hr. At $120/hr and a 90-s cycle on a 2-up tool, machine cost = ($120 / 3600 s) x 90 s / 2 = $1.50 per part. Thin-gauge roll-fed lines run faster cycles and higher cavitation, pushing machine cost per part under $0.10. The Forming Cycle Time calculator feeds this directly; a 10-second cycle improvement on a $120/hr, 4-up line saves about $0.083 per part, which is real money at 500,000 pieces.

Labor depends on automation level and secondary operations. A fully automated roll-fed line may attribute 0.05 to 0.15 labor hours per hundred parts; a manual heavy-gauge cell with hand-trim and assembly can run 0.05 to 0.25 labor hours per part. Cost secondary ops explicitly: CNC or die trimming, drilling, routing, and packing often add $0.20 to $2.00 per part and are the single most-forgotten line in a quote. If a part needs router trim at 45 s of operator time at $28/hr loaded, that is $0.35 you must not leave out.

Tooling amortization spreads mold cost across the program volume. An aluminum production tool runs $8,000 to $60,000; a prototype or wood tool $1,500 to $8,000. Amortize by dividing tool cost by committed volume: a $24,000 tool over 150,000 parts adds $0.16 per part. Over 500,000 it is $0.048. This is why low-volume quotes look expensive and buyers push for volume commitments. The Tooling Amortization calculator lets you show the customer the per-part tooling curve so the quote survives a purchasing challenge instead of looking padded.

Overhead and margin sit on top. Plant overhead (utilities, maintenance, QA, facility) is often loaded into the machine rate, but if it is separate, expect 15 to 30 percent of direct cost. Then add target margin, commonly 12 to 25 percent for contract thermoforming. Stacking the tray example: material $0.33 (net of regrind), machine $0.20, labor $0.12, tooling $0.10, subtotal $0.75, plus 20 percent overhead and 18 percent margin lands near $1.06 per part. Show the customer the stack, not just the number.

The three estimating errors that cost the most: quoting part mass instead of blank mass (understates material 25 to 45 percent), forgetting secondary trim and assembly labor, and amortizing tooling over hoped-for volume instead of the committed purchase order. A quote built on committed volume, full blank mass, actual scrap percent, and named secondary ops will hold. Rebuild any quote that came in suspiciously low against these four inputs before you sign, because the gap almost always hides in one of them.

Published 2026-07-01.