Seasonal cash flow calculator
Where do changing monthly receipts and payments create a cash shortfall?
A teaching example in the units shown below.
These authored example inputs illustrate the calculation. Replace them with your own documented amounts, periods and rates; they are not measured industry averages or available offers. The twelve-month shape is hypothetical; the tool does not infer an industry's seasonal pattern.
Cash accessible before the first planning month.
A minimum balance to test at opening and each month end. No financing is added automatically.
Use twelve distinct periods in order. Enter receipts and payments in their cash month, including operating costs, taxes, debt service, equipment, owner draws and explicitly planned financing. Count each amount once.
Your entered scenario
Starting exampleCalculation updated using the entered assumptions.
- Total cash receipts
- $131,000.00
- Total cash payments
- $132,000.00
- Net cash movement
- −$1,000.00
- First balance below the floor
- None at checked dates
Opening and month-end cash
| Period | Opening cash | Receipts | Payments | Closing cash | Shortfall to floor |
|---|---|---|---|---|---|
| Month 1 | $15,000.00 | $7,000.00 | $11,000.00 | $11,000.00 | $0.00 |
| Month 2 | $11,000.00 | $8,000.00 | $11,000.00 | $8,000.00 | $0.00 |
| Month 3 | $8,000.00 | $9,000.00 | $11,000.00 | $6,000.00 | $0.00 |
| Month 4 | $6,000.00 | $11,000.00 | $11,000.00 | $6,000.00 | $0.00 |
| Month 5 | $6,000.00 | $13,000.00 | $11,000.00 | $8,000.00 | $0.00 |
| Month 6 | $8,000.00 | $15,000.00 | $11,000.00 | $12,000.00 | $0.00 |
| Month 7 | $12,000.00 | $16,000.00 | $11,000.00 | $17,000.00 | $0.00 |
| Month 8 | $17,000.00 | $15,000.00 | $11,000.00 | $21,000.00 | $0.00 |
| Month 9 | $21,000.00 | $12,000.00 | $11,000.00 | $22,000.00 | $0.00 |
| Month 10 | $22,000.00 | $10,000.00 | $11,000.00 | $21,000.00 | $0.00 |
| Month 11 | $21,000.00 | $8,000.00 | $11,000.00 | $18,000.00 | $0.00 |
| Month 12 | $18,000.00 | $7,000.00 | $11,000.00 | $14,000.00 | $0.00 |
Formula and interpretation
Monthly net cash movement = cash receipts − cash payments
Closing cash = opening cash + monthly net cash movement
Each month's closing cash becomes the next month's opening cash.
Extra opening funding is the largest shortfall below the chosen floor across opening and month-end balances.
To reproduce the worked example, choose Hypothetical arithmetic example under Starting example. Business presets have their own inputs; compare the selected values before applying the result.
Enter actual cash timing, including operating payments, taxes, debt service, equipment and owner draws where relevant. Receipts may include funding only if you explicitly enter it.
A later recovery does not remove an earlier shortfall. Negative balances remain visible as a funding problem; the tool adds no automatic loan or cash injection.
The separate zero-cash and protected-floor gaps distinguish basic monthly liquidity from your selected cushion.
Worked example: the default twelve months receive $131,000 and pay $132,000, so $15,000 opening cash ends at $14,000. The lowest month-end is $6,000, giving only $1,000 headroom above the selected $5,000 floor despite the stronger later months.
A separate $3,000 payment in Month 3 would lower that month-end to $3,000 and require $2,000 more opening cash to preserve the floor. Use the Ice Cream Shop case to investigate actual monthly trading and payments; this hypothetical shape is not its seasonal forecast.
Definitions and sources
These references support definitions and calculation boundaries, not the selected amounts. Worked examples below use the hypothetical arithmetic inputs. A selected business preset has its own roster, cost allocation and evidence; its results can differ without a formula error.
- Cash timing and financial management — U.S. Small Business Administration. Supports distinguishing cash receipts/payment timing from accrual recognition. No seasonal series or required reserve is copied. Accessed October 4, 2026.
Continue with a related calculation
Cash runway
How long would constant monthly receipts and payments preserve your cash floor?
Open calculator →Startup cost
How much opening funding does your entered budget and reserve assumption require?
Open calculator →Profit margin
What remains after the operating expenses, interest and income-tax amount you enter?
Open calculator →Connect the calculation to a complete operating plan
Review startup uses, staffing, annual results and input evidence alongside the relevant worksheets. A single calculation does not replace local quotes or a dated cash schedule.
Read the Ice Cream Shop operating case →Check the input evidence and limits →
- Business Plan
- $59
- Financial Model
- $109
- Bundle
- $168
Choose your business to buy its plan, model or both through Shopify checkout.
Review custom-work scope →