Is the fixed change-order cost charged once or per unit?

Once. Engineering, programming and documentation for the revision are incurred one time, so the fixed amount is added once and divided across the affected units.

What does an approved scope below 100% mean?

Only part of the change is authorized. The rest is work you have estimated or absorbed but cannot bill, so track it against the order margin until the customer approves the remainder.

Should freight and expediting go into change cost per unit?

Only when the change causes them. Freight that repeats with every unit belongs in the per-unit cost, while one-off expediting belongs with the fixed change-order cost.

How do I handle a change the customer will not approve?

Hold the work and price it at full variable cost with the fixed change-order cost included. If you build unapproved changes, that cost sits in the order margin until the customer signs off.

Contract Manufacturing, Job Shop Quoting & Make-to-Order calculator

Customer Change Cost Calculator

A customer change rarely lands on every unit in an order. Enter the affected units, per-unit cost, approved scope and fixed change-order cost to price the revision.

What this calculator does

What a customer change costs once the approved scope and the one-time change-order cost are counted.

Formula used

Variable change cost = affected units × change cost per unit × approved scope share
Total change cost = variable change cost + fixed change-order cost
Total change cost per unit = total change cost ÷ affected units

Inputs explained

Units Affected by Customer Change: Units already released or made that the change touches.
Change Cost per Affected Unit: Variable cost to change one affected unit, from the estimate.
Customer-Approved Change Scope: Share of the change the customer has authorized in writing.
Fixed Change-Order Cost: One-time engineering, programming and documentation cost for the revision.

How to use the result

Best suited to pricing a revision to an open order, splitting approved and absorbed change work.
Rework and scrap caused by the change carry their own cost beyond the scope entered. A routing change can reset setup hours, which the per-unit cost does not capture.

Current U.S. benchmarks

The U.S. prime lending rate is 7.00% (Federal Reserve via FRED, 2026-10-02). Payback and financing math should start from today's rate, not a remembered one.

Common questions

Is the fixed change-order cost charged once or per unit? Once. Engineering, programming and documentation for the revision are incurred one time, so the fixed amount is added once and divided across the affected units.
What does an approved scope below 100% mean? Only part of the change is authorized. The rest is work you have estimated or absorbed but cannot bill, so track it against the order margin until the customer approves the remainder.
Should freight and expediting go into change cost per unit? Only when the change causes them. Freight that repeats with every unit belongs in the per-unit cost, while one-off expediting belongs with the fixed change-order cost.
How do I handle a change the customer will not approve? Hold the work and price it at full variable cost with the fixed change-order cost included. If you build unapproved changes, that cost sits in the order margin until the customer signs off.

Last reviewed 2026-10-01.