Editorial attribution: BizCalcAtlas editorial team. Formula and source provenance follow the published methodology.
Change Order Pricing for Service Projects explains change order pricing with the same definitions and calculation method used by the linked tools. Use the method for a consistent scenario, then verify any current rate, legal rule, or platform policy against the cited source.
Answer in brief
incremental cost = extra labor + materials + subcontractors + incremental schedule cost change price = incremental cost / (1 - target contribution margin)
Scope and definitions
This guide owns the informational intent; linked calculator pages continue to own interactive calculator intent.
The guide supports Service Pricing / Job Bid Calculator; Flat Rate Pricing Calculator; Contractor Hourly Rate Calculator. Keep the numerator, denominator, cost categories, fee base, and time period consistent from the first input through the final comparison.
Calculation method
| Step | Calculation or rule |
|---|---|
| 1 | incremental cost = extra labor + materials + subcontractors + incremental schedule cost change price = incremental cost / (1 - target contribution margin) |
Formula / rule
incremental cost = extra labor + materials + subcontractors + incremental schedule cost
change price = incremental cost / (1 - target contribution margin)
Worked example
A requested change adds $420 labor, $180 materials and $100 of schedule-related cost. Incremental cost is $700. At a 30% target contribution margin, the modeled change price is $1,000.
Practical reference
Record the relevant scenario fields together before calculating. The implementation brief calls for these comparison fields: Input, Example. Using one record prevents values from different periods or scopes from being mixed.
Common mistakes
- Using a different definition or time period from the one specified by the change order pricing method.
- Comparing outputs from Service Pricing / Job Bid Calculator; Flat Rate Pricing Calculator; Contractor Hourly Rate Calculator without holding the shared assumptions constant.
- Treating a worked scenario as a universal target instead of testing the inputs that apply to the business.
- Relying on an undated secondary claim when the listed first-party or official source governs a current rate or rule.
Frequently asked questions
Should a change order use the original hourly rate?
The answer depends on the scenario and assumptions. Use the stated method for change order pricing, then test the result with the linked calculators and verify any current rate or rule against the listed sources.
Should schedule disruption be included?
The answer depends on the scenario and assumptions. Use the stated method for change order pricing, then test the result with the linked calculators and verify any current rate or rule against the listed sources.
Can a change order reduce price?
The answer depends on the scenario and assumptions. Use the stated method for change order pricing, then test the result with the linked calculators and verify any current rate or rule against the listed sources.
When should work on the change start?
Use this method: incremental cost = extra labor + materials + subcontractors + incremental schedule cost change price = incremental cost / (1 - target contribution margin) Keep every input on the same period and definition basis.
How this guide was created and tested
- Method basis: the guide uses the same definitions and method boundaries as the linked calculator family and the audited implementation package.
- Validation coverage: the linked calculators currently contribute 6 audited release test vectors to the underlying calculation methods used by this guide.
- Source hierarchy: current rates, fees, laws, or platform rules prefer government and first-party sources; educational and industry references are supporting evidence rather than silent overrides.
- Automation and AI: automation or AI may assist drafting, organization, source grouping, and regression work, but it is not treated as an authoritative source and cannot replace the cited evidence or audited formula.
- Editorial responsibility: MIASIN S.R.O. controls publication, source policy, corrections, and release decisions. No named individual expert review is claimed unless a page explicitly identifies one.
Read the full Methodology, Editorial Standards, and Corrections Policy.
Sources and review
Sources are ordered by authority: government or official sources first, then first-party platform sources, educational references, and finally supporting industry references.
- Educational reference: OpenStax
- Educational reference: OpenStax
- Supporting industry reference: pmi.org
Last reviewed: September 29, 2026
Source set reviewed: September 29, 2026
Next scheduled review: March 29, 2027
Review guidance: Recheck change-order cost, approval delays and schedule effects.