Change Order Cost Impact Calculator
Calculate the full cost impact of a construction change order, including direct costs, overhead & profit markups, and bond/insurance premiums.
Formulas Used
1. Self-Performed Direct Cost
Direct Cost = Labor + Material + Equipment
2. Subcontractor Total
Sub Total = Subcontractor Cost × (1 + Sub Markup % / 100)
3. Total Direct Cost
Total Direct = Direct Cost + Sub Total
4. After Overhead
After Overhead = Total Direct × (1 + Overhead % / 100)
5. After Profit
Before Bond = After Overhead × (1 + Profit % / 100)
6. Total Change Order Cost
Total CO = Before Bond × (1 + Bond & Insurance % / 100)
7. Effective Markup
Effective Markup % = ((Total CO − Total Direct) / Total Direct) × 100
Assumptions & References
- Overhead and profit markups are applied sequentially: overhead is applied first to total direct cost, then profit is applied to the overhead-inclusive subtotal — consistent with standard AIA and AGC change order pricing practices.
- The subcontractor markup is applied only to the subcontractor's base cost before the general contractor's overhead and profit are applied, reflecting typical GC pass-through pricing.
- Bond and insurance rates are applied last, on the fully marked-up subtotal, as premiums are typically calculated on the total contract/change order value.
- Typical overhead markups range from 5–15%; profit markups from 5–15%; subcontractor markups from 5–10%; bond rates from 0.5–3% depending on project size and contractor risk profile (AGC, RSMeans).
- All inputs default to $0 if left blank; at least one cost field must be non-zero.
- This calculator does not account for escalation, delay damages, or time-related impact costs, which may be addressed separately in a time impact analysis (TIA).