How do you calculate retest cost in a reliability lab?

Multiply the samples needing retest by the loaded cost per sample and the retest cost share, then add fixed investigation fees. With 18 samples at $410 each, 100% cost share, plus $1,600 fees, the total is $8,980.

What does the 'retest cost share' percentage mean?

It is the fraction of the per-sample cost charged to retest rather than the original test. At 100% the full re-run cost is attributed to retest; lower it when some setup carries over from the first run.

Who pays for reliability retesting?

It depends on the failure cause. Design or part failures usually fall to the customer via a change order, while lab process errors are absorbed by the lab. This calculator quantifies the amount either way.

What is a typical cost per retested sample?

For environmental and mechanical reliability work, $300-$600 of loaded labor and chamber time per retested sample is common. In this example the effective cost is about $499 per sample after the fixed investigation fee is spread across all 18.

How do retest costs differ from initial test costs?

Retests add a failure-investigation burden and often a re-fixturing step that the first run already amortized. That is why the fixed setup and investigation fee, here $1,600, is broken out separately from the variable per-sample cost.

Environmental Test Chambers & Reliability Labs calculator

Retest Cost Calculator

Retest cost is the hidden tax on every reliability program: when a sample fails thermal cycling, HALT, or a vibration profile, the lab must investigate, re-fixture, and re-run, and that effort rarely appears in the original quote. This calculator combines the number of samples requiring retest, the loaded cost per retested sample, the share of cost actually attributable to retest, and the fixed setup and investigation fees into a single defensible figure. Reliability engineers and lab managers use it to recover retest costs in change orders, to track the cost of design immaturity, and to decide whether a borderline design is worth re-running or sending back to engineering. It makes the cost of failure visible instead of letting it quietly erode lab margin.

What this calculator does

Estimate retest cost from samples requiring retest, cost per retested sample, retest share, and setup or investigation fees.
a reliability engineer needs to estimate cost exposure from retesting
It computes the total cost of retesting failed reliability samples by multiplying sample count, loaded cost per sample, and retest cost share, then adding fixed investigation and setup fees.

Formula used

Variable retest cost = samples requiring retest × loaded cost per retested sample × retest cost share
Total retest cost = variable retest cost + retest setup and investigation fees

Inputs explained

Samples requiring retest:
Loaded cost per retested sample:
Retest cost share:
Retest setup and investigation fees:

How to use the result

Use it after a failure to scope a retest change order, or up front to reserve a contingency for expected retest activity in a qualification program.
It assumes retested samples cost roughly the same to re-run; a failure requiring chamber reconfiguration or a new fixture can cost far more than the average.

Common questions

How do you calculate retest cost in a reliability lab? Multiply the samples needing retest by the loaded cost per sample and the retest cost share, then add fixed investigation fees. With 18 samples at $410 each, 100% cost share, plus $1,600 fees, the total is $8,980.
What does the 'retest cost share' percentage mean? It is the fraction of the per-sample cost charged to retest rather than the original test. At 100% the full re-run cost is attributed to retest; lower it when some setup carries over from the first run.
Who pays for reliability retesting? It depends on the failure cause. Design or part failures usually fall to the customer via a change order, while lab process errors are absorbed by the lab. This calculator quantifies the amount either way.
What is a typical cost per retested sample? For environmental and mechanical reliability work, $300-$600 of loaded labor and chamber time per retested sample is common. In this example the effective cost is about $499 per sample after the fixed investigation fee is spread across all 18.
How do retest costs differ from initial test costs? Retests add a failure-investigation burden and often a re-fixturing step that the first run already amortized. That is why the fixed setup and investigation fee, here $1,600, is broken out separately from the variable per-sample cost.

Last reviewed 2026-05-12.