Cash Flow Calculator
Enter your bank balance and typical monthly numbers. We'll show your reserve cushion and where your balance is headed.
How to calculate and project cash flow
Cash flow is the movement of money in and out of your bank account over a period — not profit. Profit is an accrual measure that records a sale when you invoice it; cash flow records it when the money lands. A business can be profitable on paper and still miss payroll, which is why lenders, landlords, and bonding companies look at cash separately from the P&L.
This calculator projects net monthly cash flow and rolls your balance forward six months so you can see the trend, not just this month. Enter your starting bank balance, expected monthly cash inflows, expected cash outflows, and a growth rate. The result shows whether the business is self-funding, how many months of reserve you are carrying, and where the balance is heading if nothing changes.
The cash flow formulas
Net cash flow
Cash in − Cash out
Positive means the business funded itself this month. Negative means the balance sheet — or you — covered the gap.
Ending balance
Starting balance + Net cash flow
Chain this month to month and the trajectory becomes obvious long before the account runs dry.
Months of reserve
Cash on hand ÷ Monthly cash outflow
How long the business survives with zero collections. Three months is the working target for most small businesses.
How to read your result
Profit and cash diverge for four reasons
Unpaid invoices, inventory bought ahead of sales, loan principal payments that never touch the P&L, and owner draws. If profit looks fine and cash does not, the answer is almost always one of these four.
Growth consumes cash
Raise the growth rate in the calculator and watch the early months tighten. Growing businesses pay for materials, labor, and ad spend before customers pay them — the faster the growth, the wider the gap.
A thin reserve is a pricing problem in disguise
If net cash flow is positive but reserves never build, the margin is too thin to fund the business. Pair this with the profit margin and break-even calculators before you go looking for a loan.
Frequently asked questions
+How do you calculate net cash flow?
Subtract total cash paid out during the period from total cash received. Include every real movement of money — loan proceeds, loan principal payments, owner draws, and tax payments — even though several of those never appear on the profit and loss statement.
+What is the difference between cash flow and profit?
Profit records revenue when earned and expenses when incurred. Cash flow records money when it actually moves. Invoicing $40,000 in January that pays in March produces January profit and March cash. That timing gap is what causes profitable businesses to run out of money.
+How much cash reserve should a small business keep?
Three months of operating expenses is a reasonable working target, and lenders take comfort in seeing it. Seasonal businesses and contractors who carry retainage generally need more, because their inflows arrive in bursts while payroll never pauses.
+How do I improve cash flow without increasing sales?
Shorten collection terms and invoice the day work is complete, take deposits on larger jobs, negotiate longer supplier terms, remove slow-moving inventory, and move recurring services to autopay. Most small businesses find weeks of cash sitting in their receivables process before they find it in new revenue.
+How far ahead should I forecast cash?
Six months for planning and thirteen weeks for operations. The six-month view tells you whether the model works; the weekly view tells you which Friday is going to be tight. Use the 13-week cash flow forecast for the operating layer.
Want a cash forecast built from your actual bank data?
A projection built on estimates is a guess. We reconcile your accounts, pull the real inflow and outflow history, and build a forecast you can hand to a lender or use to decide whether you can afford the next hire.
Want us to review these numbers with you?
Share a few details and we'll follow up within one business day with tailored next steps — no pressure, no obligation.
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