Cash flow vs profit — they are not the same
A business can be profitable on paper and still run out of cash. Profit is an accounting concept: revenue minus expenses, including non-cash items like depreciation. Cash flow is what actually moves through the bank account: cash in minus cash out. Small businesses die from cash flow, not profitability — you can have a 20% net margin and zero cash because customers pay slowly, inventory ties up money, and big quarterly tax payments hit at bad times.
The cash flow projector above is deliberately simplified. It treats revenue as cash collected and expenses as cash paid in the same month. That makes it perfect for planning — and if you need a full accrual vs cash reconciliation, that is a job for your bookkeeping software, not a one-page calculator.
How to use this calculator
- Starting cash: the balance in your business checking account today.
- Revenue (Month 1): realistic estimate of cash collected next month, not invoiced.
- Growth % per month: how fast you expect revenue to grow. 2% per month is 27% per year.
- Expense categories: COGS grows with revenue; payroll, rent, marketing, and other are held flat unless you bake in increases.
The chart shows what the cash balance looks like over the next 12 months. If the line goes below zero, you need a plan — raise prices, cut expenses, accelerate collections, or raise capital before it becomes urgent.
The four levers of cash flow
- Revenue timing. Faster collections — deposits, shorter invoice terms, autopay — improve cash flow without changing profit.
- Revenue volume. Selling more, obviously.
- Expense timing. Negotiating Net-60 with suppliers while staying Net-15 with customers is the gold standard. You effectively finance operations with supplier credit.
- Expense volume. Cutting unnecessary subscriptions, right-sizing headcount, reducing waste.
Of the four, timing levers (1 and 3) are the fastest to move and most underused. A business with the same P&L but tighter receivables can have twice the cash on hand.
Seasonal businesses need rolling forecasts
If your business has a strong seasonal pattern — retail in Q4, landscaping in spring, accounting in tax season — a flat monthly projection understates the cash swing. Build a seasonal adjustment by dropping revenue in low months and boosting it in peak months. The right way to do this in spreadsheet form is to enter a monthly revenue pattern rather than a single number. The calculator supports a single starting number plus growth — for seasonal businesses, treat the output as a smoothed-average view and do a more detailed spreadsheet quarterly.
Accounts receivable drag
The single largest cash flow gap in service businesses is between invoice date and payment date. If you invoice $30,000 per month on Net 30, you always have roughly a month of receivables outstanding — $30,000 of earned revenue sitting on a client's desk instead of in your bank. Shortening terms to Net 15, offering a 2% discount for paying within 10 days, or collecting deposits on project start can all compress that gap. Our invoice generator adds clear due dates to every invoice.
When ending cash goes negative
If the projection shows you running out of cash in month 7, that is your signal to act now — not in month 6. Options in rough order of preference:
- Collect outstanding invoices. The fastest cash source is usually already owed to you.
- Cut controllable expenses. Pause hiring, reduce marketing spend, negotiate rent concessions.
- Raise prices. Even a 5% price increase on existing customers can close the gap.
- Sell in advance. Offer annual plans, retainers, or deposits.
- Open a line of credit. Banks will lend money when you don't need it. Apply before the crisis.
- Take a term loan. Our business loan calculator shows what monthly payments will do to the projection.
Monthly review cadence
Update the cash flow projection on the first of every month. Replace last month's projected revenue and expenses with actuals, and re-run the next 12 months. This rolling 12-month model is the foundation of any small business's financial planning, far more useful than the annual budget most owners build once a year and never touch. Fifteen minutes a month saves you from cash surprises.
Linking cash flow to strategy
Cash flow is not just operations — it reflects strategy. A growth-stage business will show negative monthly cash flow because it is reinvesting in marketing and headcount. A mature profitable business should throw off cash. If your projection shows negative cash flow and you are not in growth mode, something is broken in the unit economics. Pair the cash flow calculator with the profit margin calculator and the runway calculator to see the full picture.
Operating cash flow vs free cash flow
For most small businesses, the numbers above approximate operating cash flow — the cash produced by day-to-day operations. Free cash flow subtracts capital expenditures (new equipment, major software, renovations). If you are planning large capex in the next year, add it as a one-time expense to a specific month rather than smearing it across the projection. Capex timing has a huge cash flow impact and should be visible, not buried.