Cash inflow-outflow landscapeCapital event appears in its selected month
Business
Cash Runway Cash Flow Calculator
Create an explicit eighteen-month cash ledger instead of dividing cash by one average burn number. Revenue growth and collection lag drive receipts; variable cash cost, payroll, overhead, debt service, and scheduled capital spending drive outflows. The schedule reports closing cash, minimum liquidity, runway month, and cumulative funding need.
Month 18 closing cash-
Minimum cash balance-
Runway exhaustion month-
Total customer receipts-
Total operating outflows-
Capital spending event-
Peak monthly cash deficit-
Liquidity status-
Month 18 cash relative to opening liquidity
Eighteen-month cash ledger
Separate collected inflows from operating, financing, and investment cash
Receipts and outflowsClosing cash
| Month | Revenue | Receipts | Variable cash cost | Payroll + overhead | Debt + capex | Net cash | Closing cash |
|---|
Cash calendar setup
How to build an 18-month runway from cash receipts and payments
- Start with unrestricted cash available at the beginning of month 1.
- Project revenue, then select the whole-month collection lag that best represents billing terms.
- Separate variable cash cost from payroll, overhead, and debt service.
- Place the one-time capital purchase in the month cash actually leaves the account.
- Use the minimum balance and first negative month to plan financing lead time.
Accrual-to-cash bridge
Revenue does not protect runway until it is collected
The model generates revenue in the selling month but shifts receipts by the chosen lag. Variable costs remain tied to current-month revenue, exposing the temporary funding need created by growth. Payroll, overhead, debt service, and capex are then layered onto that collection calendar.
Detailed calculation process
Cash-flow equations with collection timing
Revenueₘ = Month-1 revenue × (1 + Growth)^(m − 1)Receiptsₘ = Revenueₘ₋lag, or 0 before the lag has elapsedOutflowsₘ = Revenueₘ × Variable-cost rate + Payroll + Overhead + Debt service + CapexₘNet cashₘ = Receiptsₘ − OutflowsₘClosing cashₘ = Opening cashₘ + Net cashₘCapital-event interpretation
A healthy operating trend can still contain a financing pinch
The chart colors the selected capital-spending month separately because a single investment can create the minimum cash point even when routine operations are improving. Moving capex changes timing, not project economics; use that comparison to plan funding rather than to erase the cost.
Opening-month cash bridge
Reconcile the first trough before trusting the 18-month curve
Month 1 receipts = $0 because the collection lag is one monthVariable cash cost = $420,000 x 28% = $117,600Fixed cash outflow = $260,000 + $115,000 + $24,000 = $399,000 Month 1 therefore closes at $1,750,000 - $117,600 - $399,000 = $1,233,400. The complete schedule then rolls delayed receipts, growth, and the month-6 capital purchase forward to a month-18 balance of $942,943, with a minimum cash point of $455,156.
Treasury extensions
When to replace the simple lag
- Model customer-specific collection curves
- Add payroll dates and tax-payment months
- Separate maintenance and growth capex
- Include revolver draws, interest, and covenant headroom
Simplification
A whole-month lag is an approximation
Real collections arrive across days and may include deposits, bad debt, late payments, and seasonal billing. The result is a planning envelope, not a bank-statement forecast.
Cash runway cash flow FAQ
Questions about timing and runway
Why can growth reduce cash?
Current costs can rise before delayed customer receipts arrive.
What does “beyond month 18” mean?
The modeled balance remains nonnegative through the displayed horizon; it is not an indefinite-runway claim.
Should debt service include principal?
Yes. Enter the recurring cash payment, including principal and interest, for a liquidity view.
Practical examples
Cash Runway Cash Flow Calculator in real planning situations
- Model a one-month collection delay during rapid growth.
- Place a capital purchase in a specific month and see its runway effect.
- Separate gross operating contribution from debt and investment cash commitments.
Important note
Before relying on this result
Calculated from the entered values using the displayed accounting method. Reconcile material decisions with source records and applicable accounting policy.
Additional Cash Runway Cash Flow Calculator questions
Why can receipts differ from revenue?
The entered collection lag shifts modeled customer cash into later months.
How is capital spending scheduled?
The entered amount is paid once in the selected month.
What does runway month mean?
It is the first month with a negative closing cash balance; if none occurs, runway extends beyond the 18-month display.
Does the ledger include taxes?
Only if taxes are included in overhead or another entered cash outflow.