How do you calculate rework cost from prescription errors?

Multiply the number of error orders by the variable remake cost per order, then add fixed remake setup cost and investigation overhead. With 24 orders at $78, plus $180 setup and $320 overhead, total cost is $2,372.

What is the cost per affected order in this example?

Dividing the $2,372 total by 24 prescription-error orders gives $98.83 per affected order, which is higher than the $78 variable rate because it spreads fixed setup and investigation overhead across the batch.

Why is the per-order cost higher than the variable remake cost?

The $78 variable cost only covers the second pass of materials and labor. The per-order figure of $98.83 also carries the $500 in fixed setup, investigation, and overhead, which is the part most labs forget to count.

What counts as a prescription error in a lens lab?

Wrong sphere, cylinder, axis, add power, prism, or PD entered or transcribed incorrectly, plus base-curve and material mismatches that force a full remake rather than a recoat or re-edge.

How do I lower prescription-error rework cost?

Add Rx-data validation at order entry, require a second verification before surfacing, and lensometer-verify high-power and progressive jobs at final inspection. Cutting the 24 error orders in half would roughly halve the variable portion and pull total cost toward $1,400.

Should investigation time be included in rework cost?

Yes. Root-cause investigation, customer communication, and rescheduling are real overhead. Folding the $320 adder in is what moves the honest per-order cost from $78 to nearly $99.

Eyewear, Lenses & Vision Products calculator

Rework From Prescription Error Calculator

Rework from prescription error measures the true cost of remaking lenses and finished pairs when the wrong power, axis, add, or PD makes it through to the surfacing or edging line. Lab managers and optical quality leads use it to put a dollar figure on Rx-data and order-entry mistakes that otherwise hide inside scrap and overtime. Because a single remake ties up surfacing, AR coating, and edging capacity a second time, the loaded cost is almost always higher than people guess. Tracking it month over month is the fastest way to justify spend on order-entry validation and Rx verification gates.

What this calculator does

Estimate remake or rework cost caused by prescription entry, verification, measurement, or production-routing errors.
a lab manager needs to measure the cost of Rx error remakes
It computes the total cost of remaking prescription-error orders plus the average cost per affected order, separating variable remake cost from fixed setup and investigation overhead.

Formula used

Total prescription-error rework cost = rework orders × variable rework cost per order + fixed remake setup cost + investigation and overhead adder
Cost per affected order = total prescription-error rework cost ÷ prescription-error rework orders

Inputs explained

Prescription-error rework orders:
Variable rework cost per order:
Fixed remake setup cost:
Investigation and overhead adder:

How to use the result

Use it when reviewing a batch of failed verifications, building a monthly quality cost report, or justifying an order-entry validation project against the cost of remakes.
It treats every error order at one average variable cost; a progressive lens remake with a fresh AR coat costs far more than a single-vision stock remake, so blend your inputs by product mix or run them separately.

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 rework cost from prescription errors? Multiply the number of error orders by the variable remake cost per order, then add fixed remake setup cost and investigation overhead. With 24 orders at $78, plus $180 setup and $320 overhead, total cost is $2,372.
What is the cost per affected order in this example? Dividing the $2,372 total by 24 prescription-error orders gives $98.83 per affected order, which is higher than the $78 variable rate because it spreads fixed setup and investigation overhead across the batch.
Why is the per-order cost higher than the variable remake cost? The $78 variable cost only covers the second pass of materials and labor. The per-order figure of $98.83 also carries the $500 in fixed setup, investigation, and overhead, which is the part most labs forget to count.
What counts as a prescription error in a lens lab? Wrong sphere, cylinder, axis, add power, prism, or PD entered or transcribed incorrectly, plus base-curve and material mismatches that force a full remake rather than a recoat or re-edge.
How do I lower prescription-error rework cost? Add Rx-data validation at order entry, require a second verification before surfacing, and lensometer-verify high-power and progressive jobs at final inspection. Cutting the 24 error orders in half would roughly halve the variable portion and pull total cost toward $1,400.

Last reviewed 2026-05-12.