How do you calculate total scratch defect cost?

Multiply scratched units by cost per defect and by the assigned share, then add fixed containment cost. For 38 defects at $42 each, 100% assigned, plus $350 fixed: 38 x 42 x 1.00 = $1,596 variable, + $350 = $1,946 total.

What is the average cost per scratched lens or pair?

Divide total cost by the number of defects. Here $1,946 across 38 defects is about $51.21 per scratched lens or pair, higher than the $42 variable cost because fixed containment spreads across the defects.

What does the assigned share percentage do?

It allocates the variable defect cost to a specific line, shift, or root cause. At 100% the full $1,596 lands on this scope; at 50% only $798 would, which is useful when a defect is shared across responsible areas.

What belongs in fixed scratch containment cost?

Costs that do not scale with defect count — added 100% inspection, screening labor, temporary protective tooling, or a containment audit. In the example this $350 raises the per-defect average well above the raw scrap cost.

Why is the per-defect average higher than the cost per defect?

Because fixed containment cost is spread across the defect count. The $42 variable cost becomes a $51.21 effective cost per unit once the $350 fixed containment is included — the gap shows how much containment itself adds.

How do I use this to prioritize a fix?

Compare total scratch cost against the cost of a fix — better handling trays, edging fixturing, or a coating change. If a $1,946-per-window loss recurs every shift, even a several-thousand-dollar fix pays back quickly.

Eyewear, Lenses & Vision Products calculator

Scratch Defect Cost Calculator

Scratch defect cost is the total money lost to scratched lenses or finished pairs in a production window — the scrapped or reworked material plus the fixed cost of containing the problem. Quality engineers and lab managers use it to put a dollar figure on a defect mode that is easy to dismiss one lens at a time but compounds fast across a shift. By separating the per-defect variable cost, the share assigned to a given line or scope, and fixed containment spending such as inspection or screening, it turns a scratch tally into a number that competes for capital and process-fix priority.

What this calculator does

Estimate the cost impact of scratched lenses or finished pairs using defect count, replacement/rework cost, affected share, and fixed containment cost.
a quality engineer needs to estimate cost from scratched lenses in a production period
It computes total scratch defect cost by combining per-defect variable loss (scaled by the assigned share) with a fixed containment cost.

Formula used

Variable scratch defect cost = scratched lenses or pairs × cost per scratch defect × assigned defect cost share
Total scratch defect cost = variable scratch defect cost + fixed scratch containment cost

Inputs explained

Scratched lenses or pairs:
Cost per scratch defect:
Defect cost assigned to this scope:
Fixed scratch containment cost:

How to use the result

Use it when building a cost-of-poor-quality case, prioritizing which defect mode to fix first, or justifying spend on handling, fixturing, or coating-process improvements.
It captures direct scrap and containment cost but not downstream effects like remake turnaround delays, customer remakes, or lost goodwill, so it is a floor on true scratch cost.

Current U.S. benchmarks

U.S. manufacturing runs at 75.6% of capacity with new factory orders at $657B per month (Federal Reserve and Census, May 2026).

Common questions

How do you calculate total scratch defect cost? Multiply scratched units by cost per defect and by the assigned share, then add fixed containment cost. For 38 defects at $42 each, 100% assigned, plus $350 fixed: 38 x 42 x 1.00 = $1,596 variable, + $350 = $1,946 total.
What is the average cost per scratched lens or pair? Divide total cost by the number of defects. Here $1,946 across 38 defects is about $51.21 per scratched lens or pair, higher than the $42 variable cost because fixed containment spreads across the defects.
What does the assigned share percentage do? It allocates the variable defect cost to a specific line, shift, or root cause. At 100% the full $1,596 lands on this scope; at 50% only $798 would, which is useful when a defect is shared across responsible areas.
What belongs in fixed scratch containment cost? Costs that do not scale with defect count — added 100% inspection, screening labor, temporary protective tooling, or a containment audit. In the example this $350 raises the per-defect average well above the raw scrap cost.
Why is the per-defect average higher than the cost per defect? Because fixed containment cost is spread across the defect count. The $42 variable cost becomes a $51.21 effective cost per unit once the $350 fixed containment is included — the gap shows how much containment itself adds.

Last reviewed 2026-05-12.