How do you calculate cost per seal?

Add allocated variable cost (parts × variable cost × allocation share) to fixed setup/tooling, then divide by the part count. The example totals $2,950 over 5,000 seals, or $0.59 each.

Why is my per-seal cost higher on small runs?

Fixed setup and tooling are spread over fewer pieces. The $850 fixed cost here adds only $0.17/seal across 5,000 parts but would add $8.50 each across just 100.

What is cost allocation share for?

It is the fraction of variable cost charged to this job — useful when a compound batch or shared setup serves several parts. At 100% the full variable cost applies, giving $2,100 variable here.

What is a typical cost per O-ring or gasket?

Commodity O-rings can run cents apiece while specialty FKM or large gaskets cost dollars; the example's $0.59 is typical for a mid-volume molded seal once tooling is amortized.

Total cost vs cost per seal — which do I quote on?

Quote the customer on cost per seal (plus margin) but check total cost to confirm the fixed setup is recovered; here $2,950 total backs the $0.59 piece price.

How do I lower my cost per seal?

Run larger batches to dilute the $850 fixed cost, cut scrap to lower effective variable cost, and increase cavitation so each cycle yields more finished seals.

Gaskets, Seals, O-Rings & Elastomer Components calculator

Cost Per Seal Calculator

Cost per seal is the fully loaded unit cost of a molded gasket, O-ring or seal once both variable material/labor cost and fixed setup or tooling are spread across the run. Estimators, cost engineers and sales teams use it to quote rubber jobs, decide minimum order quantities and judge whether a tool amortizes over the volume on the table. Because elastomer tooling and press setup are fixed regardless of run size, the per-piece number swings hard on small lots — making this the calculation that decides if a short run is profitable. It also exposes how much of your price is material versus tool recovery.

What this calculator does

Estimate cost per finished seal or gasket using production quantity, variable cost per seal, allocation share, and fixed setup or tooling cost.
Use it when quoting molded seals, die-cut gaskets, O-rings, extruded seals, adhesive-backed gaskets, or custom elastomer components and the estimator needs a practical finished cost.
It computes the total cost of a seal run and the resulting cost per finished piece by combining allocated variable cost with fixed setup or tooling.

Formula used

Variable finished seal cost = finished seals or gaskets × variable cost per seal × cost allocation share
Total finished seal cost = variable finished seal cost + fixed setup or tooling cost

Inputs explained

Finished seals or gaskets:
Variable cost per seal:
Cost allocation share:
Fixed setup or tooling cost:

How to use the result

Use it when quoting a job, setting an MOQ, or comparing the unit economics of running a tool at different batch sizes.
It assumes a single uniform variable cost per seal; if material grade, cavitation or scrap differs across the run, blend or segment the cost first.

Current U.S. benchmarks

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 cost per seal? Add allocated variable cost (parts × variable cost × allocation share) to fixed setup/tooling, then divide by the part count. The example totals $2,950 over 5,000 seals, or $0.59 each.
Why is my per-seal cost higher on small runs? Fixed setup and tooling are spread over fewer pieces. The $850 fixed cost here adds only $0.17/seal across 5,000 parts but would add $8.50 each across just 100.
What is cost allocation share for? It is the fraction of variable cost charged to this job — useful when a compound batch or shared setup serves several parts. At 100% the full variable cost applies, giving $2,100 variable here.
What is a typical cost per O-ring or gasket? Commodity O-rings can run cents apiece while specialty FKM or large gaskets cost dollars; the example's $0.59 is typical for a mid-volume molded seal once tooling is amortized.
Total cost vs cost per seal — which do I quote on? Quote the customer on cost per seal (plus margin) but check total cost to confirm the fixed setup is recovered; here $2,950 total backs the $0.59 piece price.

Last reviewed 2026-05-12.