Project Payment Schedule Calculator
Generate a milestone-based payment schedule for your contracting project, including deposit, progress payments, and final payment amounts with due dates.
Formulas Used
Deposit Amount = Total Contract Value × (Deposit % ÷ 100)
Retainage Total = Total Contract Value × (Retainage % ÷ 100)
Progress Pool = Total − Deposit − (Total × Final %) − Retainage Total
Net Payment per Milestone = Progress Pool ÷ Number of Milestones
Retainage Withheld per Milestone = Retainage Total ÷ Number of Milestones
Final Payment = (Total × Final %) + Retainage Total (retainage released)
Milestone Date = Start Date + Round(Duration × i ÷ (Milestones + 1)) days
Verification: Deposit + Σ(Net Progress Payments) + Final Payment = Total Contract Value
Assumptions & References
- Deposit is capped at 50% per common contractor licensing regulations (e.g., California CSLB limits deposits to 10% or $1,000).
- Retainage (typically 5–10%) is withheld from each progress payment and released upon project completion per AIA Document A201.
- Progress milestones are evenly distributed across the project timeline; adjust dates in your contract as needed.
- Final payment percentage is applied to the original contract value before retainage release.
- All amounts are in USD. Tax, change orders, and lien waivers are not included.
- References: AIA A101 Standard Form of Agreement, ConsensusDocs 200, CSLB Contractor License Law.