Contractor Cash Flow Simulator
Spot the cash gap between paying your crew and getting paid.
Timing matters as much as profitability.
| Month | Opening | Received | Paid | Net | Closing | Receivables |
|---|---|---|---|---|---|---|
| 1 | $15,000.00 | $0.00 | $15,000.00 | -$15,000.00 | $0.00 | $20,000.00 |
| 2 | $0.00 | $18,000.00 | $15,000.00 | $3,000.00 | $3,000.00 | $22,000.00 |
| 3 | $3,000.00 | $18,000.00 | $15,000.00 | $3,000.00 | $6,000.00 | $24,000.00 |
| 4 | $6,000.00 | $18,000.00 | $15,000.00 | $3,000.00 | $9,000.00 | $26,000.00 |
| 5 | $9,000.00 | $18,000.00 | $0.00 | $18,000.00 | $27,000.00 | $8,000.00 |
| 6 | $27,000.00 | $0.00 | $0.00 | $0.00 | $27,000.00 | $8,000.00 |
With one additional month of delay, the funding gap becomes $15,000.00.
Your financial inputs stay in this browser. Results are planning estimates, not guaranteed outcomes or professional advice.
The math, without the mystery.
What this calculator does
Spot the cash gap between paying your crew and getting paid. It separates the parts of your estimate so you can examine what changes when a price, cost, or timing assumption changes.
Who should use it
Contractors using progress billing, delayed payment terms, or retainage.
How to use it
Replace the hypothetical inputs with figures from your estimate, contract, or business budget. Enter dollar amounts in USD and percentages as whole percentages: enter 20 for 20%. Results recalculate immediately. Use Reset to return to the example and compare a revised scenario.
How the calculation works
Regular receipts arrive invoice month + payment delay. Retainage = invoice balance after advance credit × retainage rate. Release occurs no earlier than the regular payment due month. Closing cash = opening cash + receipts + other inflows − expenses − other outflows. Funding gap = max(0, −lowest balance).
A worked example
A hypothetical $20,000 month-1 invoice with 10% retainage and a one-month delay pays $18,000 in month 2. The remaining $2,000 waits for release. Paying $12,000 in month 1 from $5,000 opening cash produces a $7,000 funding gap even though the job may be profitable.
Common mistakes
An invoice is not cash in the bank. Do not add an advance to invoice revenue: this model credits the advance against the earliest billings. Negative other cash flow means a cash outflow.