How do you calculate seal molding cost?

Multiply seals by cost per seal by first-pass yield, then add the setup and cure charge. For 5,000 seals at $0.42 with 96% yield plus a $320 charge: 5000 x 0.42 x 0.96 = $2,016 variable, + $320 = $2,336 total.

What is the cost per molded seal in the example?

Total cost of $2,336 divided by 5,000 seals gives $0.4672 per seal, which is above the raw $0.42 molded cost once yield loss and the setup charge are spread across the run.

Why is per-seal cost higher than the molded cost per seal?

The raw molded cost ignores the fixed setup and cure charge and the seals lost to yield. Both get spread across only the good pieces, pushing the effective per-seal cost up, especially on short runs.

How does first-pass yield affect molding cost?

Lower yield raises effective cost per good seal because scrapped parts still consumed compound, press time, and cure. Moving from 96% to 90% yield on this job would raise the variable cost and the per-piece number noticeably.

Compression vs injection molding cost for seals?

Compression tooling is cheaper to set up but slower and often lower yield on complex profiles; injection has higher setup and cure charges but better per-piece cost and yield at volume. This calculator lets you plug either process's numbers in.

How do I lower molded seal cost?

Raise first-pass yield through better flash control and cure optimization, amortize the setup charge over a longer run, and reduce cavity cycle time. Setup amortization is usually the biggest lever on small batches.

Rubber, Tires, Foam & Elastomer Manufacturing calculator

Seal Molding Cost Calculator

Seal molding cost captures what it actually costs to run a batch of compression- or injection-molded rubber seals, blending the per-piece molded cost, first-pass yield, and the fixed mold setup and cure charge. Estimators and process engineers in seal shops use it to price O-rings, lip seals, and custom profiles where a short-run setup can dwarf the material cost. Because yield on rubber molding is rarely 100%, folding first-pass yield into the number keeps quotes honest and prevents underpricing. The calculator returns both total job cost and a true per-good-seal cost.

What this calculator does

Estimate the cost to mold rubber seals or O-rings, combining per-piece molded cost, first-pass yield and press setup.
An estimator uses it to quote a compression or injection seal molding run for a given annual volume.
It multiplies seals by molded cost per seal and by first-pass yield to get the variable cost, adds the fixed setup and cure charge, and divides by piece count for a per-seal cost.

Formula used

Seal molding cost = seals x cost per seal x first-pass yield% + setup/cure charge
Cost per seal = total molding cost / seals

Inputs explained

Seals Molded:
Molded Cost per Seal:
First-Pass Yield:
Mold Setup & Cure Charge:

How to use the result

Use it when quoting a molded seal run or reviewing whether a low-yield tool is eroding margin on an existing program.
Treating yield as a simple multiplier assumes rejected seals still consume their full molded cost; it does not separately model rework, regrind recovery, or scrap disposal.

Current U.S. benchmarks

The producer price index for plastic resins and materials stands at 319.371 (BLS, May 2026), up 19.5% from a year earlier. Quotes priced off last quarter's material cost miss this move.
U.S. light vehicles sell at a 16.9 million annual rate (BEA, Jun 2026), up 4.1% from a year earlier, the volume signal for automotive supply chains.
The U.S. has 11,391 plastics and rubber products establishments employing about 815,988 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate seal molding cost? Multiply seals by cost per seal by first-pass yield, then add the setup and cure charge. For 5,000 seals at $0.42 with 96% yield plus a $320 charge: 5000 x 0.42 x 0.96 = $2,016 variable, + $320 = $2,336 total.
What is the cost per molded seal in the example? Total cost of $2,336 divided by 5,000 seals gives $0.4672 per seal, which is above the raw $0.42 molded cost once yield loss and the setup charge are spread across the run.
Why is per-seal cost higher than the molded cost per seal? The raw molded cost ignores the fixed setup and cure charge and the seals lost to yield. Both get spread across only the good pieces, pushing the effective per-seal cost up, especially on short runs.
How does first-pass yield affect molding cost? Lower yield raises effective cost per good seal because scrapped parts still consumed compound, press time, and cure. Moving from 96% to 90% yield on this job would raise the variable cost and the per-piece number noticeably.
Compression vs injection molding cost for seals? Compression tooling is cheaper to set up but slower and often lower yield on complex profiles; injection has higher setup and cure charges but better per-piece cost and yield at volume. This calculator lets you plug either process's numbers in.

Last reviewed 2026-05-12.