Price a change order after labor, materials, schedule delay, overhead, disruption, payment fees, commission and expected callback risk.
Model reviewed September 4, 2026 · Inputs stay in your browser
Decision model
The formula
True change cost = direct cost + delay overhead + disruption reserve + expected callback reserve. Target price solves for the requested margin after transaction leakage.
This tool is designed to combine assumptions that are usually split across several simpler calculators. Every real-world rate is editable.
Enter your assumptions and calculate.
What simple bid math misses
A change order can add days to a project, interrupt crew productivity, create extra payment fees or commission, and increase the chance of a callback. Those costs do not disappear because they are not printed on a material receipt.
Target price vs markup
The target-price calculation works from margin, not markup. If you want a 30% margin, adding 30% to cost is not enough. The price must be high enough for profit to remain 30% of the final selling price after leakage.
Use a reserve, not a prediction
The callback and disruption fields are expected-value reserves. They are not claims that a callback will happen. They simply force recurring risk into the price instead of pretending it costs zero.
Why this calculator exists
There are many good single-formula calculators. This one is intentionally more complex: it helps answer a decision where several risks and costs interact. Complexity is useful only when the extra inputs change what you would do.
Spreadsheet version
Want to save or modify this model?
Use the matching Contractor Change Order Profit Impact Google Sheets template to keep scenarios, change assumptions or extend the model.