Free valuation & inventory tool
Cash Flow Calculator with 12-Month Projection
Monthly operating cash flow is the cash collected from patients minus the cash paid out for supplies, payroll, rent, loan payments and other costs. If you collect $120,000 and pay out $110,000, cash flow is $10,000 a month. This cash flow calculator shows that number, projects your bank balance for 12 months with growth you set, and tells you how many months of runway you have.
Prepared by Prospyr · Reviewed October 3, 2026 · Free, no sign-up, runs in your browser
Money that lands in the bank, not invoices sent. Include memberships and package prepayments when they are paid.
Cash paid out ($ per month)
0 keeps it flat.
Monthly operating cash flow
$10,000
More cash is coming in than going out this month.
Cash out per month
$110,000
Balance after 12 months
$180,000
projected
Lowest balance
$70,000
within 12 months
Runway
Not at risk
within 10 years
A projection from your own inputs, not financial advice. It ignores seasonality, taxes due, owner draws and one-time purchases unless you include them above.
12-month cash projection
| Month | Cash in | Cash out | Net | Ending cash |
|---|---|---|---|---|
| 1 | $120,000 | $110,000 | $10,000 | $70,000 |
| 2 | $120,000 | $110,000 | $10,000 | $80,000 |
| 3 | $120,000 | $110,000 | $10,000 | $90,000 |
| 4 | $120,000 | $110,000 | $10,000 | $100,000 |
| 5 | $120,000 | $110,000 | $10,000 | $110,000 |
| 6 | $120,000 | $110,000 | $10,000 | $120,000 |
| 7 | $120,000 | $110,000 | $10,000 | $130,000 |
| 8 | $120,000 | $110,000 | $10,000 | $140,000 |
| 9 | $120,000 | $110,000 | $10,000 | $150,000 |
| 10 | $120,000 | $110,000 | $10,000 | $160,000 |
| 11 | $120,000 | $110,000 | $10,000 | $170,000 |
| 12 | $120,000 | $110,000 | $10,000 | $180,000 |
Cash flow formula and the 12-month projection
- Operating cash flow = cash in − cash out
- Ending cash = starting cash + operating cash flow for the month
- Growth: month m amount = month 1 amount × (1 + rate)m−1
- Runway = months until ending cash goes below $0 (shown if it happens within 10 years)
The SBA tells new businesses to build cash flow statements into their financial plan and to use monthly or quarterly projections for the first year. This tool makes a simple version for a practice that already has numbers to start from.
Worked example: a practice with $60,000 in the bank
| Line | Per month |
|---|---|
| Cash collected | $120,000 |
| Product and supplies | −$25,000 |
| Payroll and contractors | −$55,000 |
| Rent and utilities | −$12,000 |
| Loan and lease payments | −$8,000 |
| Marketing, software, insurance, other | −$10,000 |
| Operating cash flow | $10,000 |
Starting at $60,000 with flat cash flow, the balance is $70,000 after month 1 and $180,000 after month 12. Drop cash collected to $100,000 and cash flow turns to −$10,000 a month, so $60,000 lasts 6 months. Change one input at a time to see which line the balance is most sensitive to.
Using the runway number
A runway under a year is a prompt to look at the largest lines: payroll, product cost and loan payments. Seasonal swings are not modeled, so run the tool twice, once with your best months and once with your slowest. For an equipment purchase or a remodel, subtract the cost from the cash in the bank before reading the runway.
Pair this with the inventory turnover calculator, because slow-moving product ties cash up on a shelf. Prospyr's analytics show revenue by service, so you can see which services bring in the cash entered above.
Frequently asked questions
How do you calculate monthly cash flow?
Subtract total cash paid out in the month from total cash received in the month. Count when money moves, not when you invoice or when an expense is booked. A practice that collects $120,000 and pays out $110,000 has $10,000 of operating cash flow.
What is cash runway?
Runway is how many months you can keep paying costs before the bank balance reaches zero, given your current cash and monthly burn. With $60,000 in the bank and $10,000 more going out than coming in each month, runway is 6 months. If cash flow is positive there is no runway limit to calculate.
Why is profit different from cash flow?
Profit follows accounting rules, and cash flow follows the bank. Equipment purchases, loan principal, owner draws, prepaid packages and timing of payroll and tax payments move cash without changing profit the way you might expect. A practice can show a profit and still run short of cash.
Should memberships and package prepayments count as cash in?
Count them in the month the money is collected, because that is when it is in your bank. Remember that prepaid packages create future treatments you owe, so spending the whole prepayment can leave a gap later. Keep the portion tied to unused treatments in view when you read the projection.
What growth rate should I enter?
Start at 0% to see the flat picture, then try small changes such as 1% or 2% per month in cash in or cash out. A growth rate compounds, so 2% a month is about 27% over a year. Use a number you can support from your own recent months, not a hope.
How much cash should a practice keep on hand?
There is no single rule. For startup planning, the SBA suggests counting at least one year of monthly expenses. Pick a target with your CPA, then use the runway number to check where you stand against it.
Sources and scope
- Write your business plan. U.S. Small Business Administration
Says a financial plan should include forecasted income statements, balance sheets and cash flow statements, with monthly or quarterly detail in the first year.
- Calculate your startup costs. U.S. Small Business Administration
Recommends counting at least one year of monthly expenses when estimating startup costs.
A projection from your own inputs, not financial, tax or legal advice. It does not model seasonality, taxes, owner draws or one-time purchases unless you include them.