Cash Flow Forecast Calculator

Cash flow is the net amount of money moving in and out of your business each month. Positive cash flow means you bring in more than you spend. Even profitable businesses can fail if they run out of cash — profitability on paper does not guarantee cash in the bank, especially when customers pay late.

Subtract your total monthly costs (fixed costs like rent, salaries, and subscriptions plus variable costs like COGS and commissions) from your monthly revenue. The result is your net monthly cash flow. If positive, you are generating surplus cash. If negative, you are burning through reserves.

Cash runway is the number of months your business can survive at the current burn rate before running out of cash. Most advisors recommend at least 6-12 months of runway. Startups seeking funding should aim for 18+ months. Less than 3 months of runway is a critical risk signal.

Accounts receivable days measure how long it takes to collect payment from customers. Higher AR days mean your revenue is tied up longer, creating a gap between earning and receiving cash. If you have 60-day payment terms but pay suppliers in 15 days, you fund that 45-day gap from reserves.

A cash flow margin above 10% is generally considered healthy. Margins of 20%+ provide a strong buffer for growth, unexpected expenses, and economic downturns. Negative margins require immediate attention — you are spending more than you earn and will eventually exhaust your reserves.