Cash Flow Calculator

What is cash flow runway? Cash flow runway is the number of months your business can keep operating before cash runs out — calculated as cash on hand divided by net monthly burn (expenses minus revenue). For a pre-profit DTC brand with $150K cash and $15K monthly burn, runway is 10 months. It is the most critical financial metric for growing ecommerce businesses, especially those that are pre-profit or investing heavily in inventory and advertising. It answers the fundamental question every founder needs to know: how many months can you continue operating before you run out of money?

The calculation is simple in concept — cash on hand divided by monthly net burn (expenses minus revenue). But the growth component makes it more nuanced. A business losing $15,000 per month but growing revenue at 5% month-over-month will reach breakeven much sooner than the static calculation suggests. This calculator models both the static runway and the dynamic runway with growth factored in.

The 12-month projection table shows your cash balance at the end of each month, making it easy to see when you cross zero (run out of cash) or when revenue catches up to expenses (reach breakeven). For businesses with seasonal revenue patterns, you can adjust the growth rate to reflect expected seasonality — though this simplified model assumes consistent month-over-month growth.

Key decision thresholds: below 6 months runway, you need to either raise capital, cut expenses, or accelerate revenue growth immediately. Between 6 and 12 months, you have time to execute but should be actively working toward profitability. Above 12 months gives comfortable room to invest in growth. For ecommerce brands, the biggest cash flow traps are inventory purchases (tying up cash 60 to 90 days before it converts to revenue), seasonal ad spend increases, and scaling too fast before unit economics are proven.