Cash Flow Calculator
Cash position forecast.
Project ending cash and runway from starting balance, monthly inflows, and outflows — see when the runway runs out at the current burn.
What this tool does
This tool forecasts your cash position month by month, showing how your available funds will change based on starting cash, monthly inflows, and monthly outflows over a chosen period. The result illustrates your projected cash balance at each stage, helping you see when cash might run low or accumulate. Monthly revenue and expenses drive the forecast most directly—changes to either shift the trajectory significantly. A common scenario involves a startup modeling six to twelve months ahead to identify potential shortfalls. The calculation assumes consistent monthly figures and does not account for irregular expenses, seasonal variations, working capital timing, or external financing. Results are estimates for illustration and planning purposes, not predictions of actual cash flow.
Enter Values
People also use
Money Insights
Burn Rate Calculator
Calculate your burn rate and savings rate. See what percentage of income is consumed and how much remains for wealth building.
Business & Startup
Free Cash Flow Calculator
Calculate free cash flow from revenue, operating costs, taxes, and capex — the cash a business actually has left after running and maintaining itself.
Business & Startup
Operating Cash Flow Calculator
Calculate operating cash flow from net income, depreciation, and working capital change — the cash version of the income statement bottom line.
Formula Used
Spotted something off?
Calculations or display — let us know.
Disclaimer
Results are estimates for educational purposes only. They do not constitute financial advice. Consult a qualified professional before making financial decisions.
Cash flow forecasting projects month-by-month what's in the bank, spotting shortfalls before they happen. Start with current cash, add monthly revenue (growing over time), subtract monthly expenses. The result shows ending cash each month and the lowest point along the way - the 'cash valley' that signals when overdraft or funding is needed.
50k starting cash with 20k monthly revenue and 22k monthly expenses burns 2k/month. Without growth, that's 24k/year burn, hitting zero in 25 months. Add 10% annual revenue growth and the business becomes cash-positive around month 12, ending year 1 at 56k.
Most small businesses fail from cash flow, not profit. A profitable business with 60-day customer payment terms and 30-day supplier terms can run out of cash while booking record revenue. This tool doesn't solve cash timing within a month, but the month-level forecast catches the bigger problem: whether you're heading toward an empty account.
Run it with sensible defaults
Using starting cash of 50,000, monthly revenue of 20,000, monthly expenses of 22,000, months to forecast of 12 months, the calculation works out to -37,311.366,000.00. The defaults are meant as a starting point, not a recommendation.
The levers in this calculation
The inputs — Starting Cash, Monthly Revenue, Monthly Expenses, Months to Forecast, and Revenue Growth % (annual) — do not pull with equal force. Not every input has equal weight. Adjusting one input at a time toward extreme values shows which ones move the result most.
How the math works
For each month: cash = cash + revenue - expenses. Revenue grows by (annual growth ÷ 12) monthly. Track lowest point and months in deficit.
Using this as a check-in
Re-run this every three months. A single reading tells you where you stand; four readings tell you whether things are improving. The trend matters more than any individual snapshot.
What this doesn't capture
The score is a composite of the inputs you provide. Life context — job security, family obligations, health, housing — doesn't appear in the math but shapes the real picture. Use the number as a prompt, not a verdict.
££20,000 + (£15,000-£18,000)×12m = -16,000.00.
Inputs
This example uses typical values for illustration. Adjust the inputs above to match a specific situation and see how the result changes.
Sources & Methodology
Methodology
Ending cash = starting + (inflow - outflow) × months. Runway = starting / |net monthly| if negative.
References
Frequently Asked Questions
Cash flow vs profit?
What's runway?
How often to forecast?
What if cash flow goes negative?
Related Calculators
Burn Rate Calculator
Calculate your burn rate and savings rate. See what percentage of income is consumed and how much remains for wealth building.
Free Cash Flow Calculator
Calculate free cash flow from revenue, operating costs, taxes, and capex — the cash a business actually has left after running and maintaining itself.
More Business & Startup Calculators
Business & Startup
Accounts Payable Turnover Calculator
Calculate accounts payable turnover and days payable outstanding from supplier purchases and average AP. Free educational tool.
Business & Startup
Accounts Receivable Turnover Calculator
Calculate accounts receivable turnover and days sales outstanding from credit sales and average AR — how fast your invoices actually convert.
Business & Startup
Adjusted EBITDA Calculator
Calculate adjusted EBITDA with add-backs for owner compensation, one-off costs, and non-recurring items — the version a buyer or lender will actually use.
Business & Startup
Airbnb Host Profit Calculator
Calculate Airbnb host profit by entering your nightly rate, occupancy, fees, cleaning costs, mortgage, and expenses to see monthly and annual net profit.
Business & Startup
Asset Turnover Calculator
Calculate asset turnover ratio from revenue and total assets — a measure of how efficiently a business generates sales from its asset base.
Business & Startup
Break-Even Calculator
Calculate break-even point. Enter fixed costs, selling price, and variable cost to see units needed to cover costs. Free and educational.
Explore Other Financial Tools
Utilities
Standing Charge Calculator
Calculate the annual fixed standing charges on electricity, gas, water, and other utilities. See total you pay regardless of usage.
Investing
Windfall Allocation Calculator
Model optimal windfall distribution between debt repayment, savings growth, and discretionary spending with adjustable allocation percentages.
Savings
Savings Projection by Rate Calculator
Compare how savings grow at low, medium, and high expected return rates — see how sensitive your end balance is to the rate assumption.