Key Cash Flow Metrics Every Seller Should Track
1. Operating Cash Flow
What it measures: The net cash generated or consumed by your core business operations during a specific period. This is total cash received from sales minus total cash paid for operating expenses (inventory, advertising, shipping, fees, rent, payroll, software).
Formula: Cash received from customers minus cash paid for operating expenses.
Benchmark: Positive operating cash flow in most months. Occasional negative months are normal (large inventory purchase, seasonal dip), but three or more consecutive negative months signals a structural problem. Healthy ecommerce businesses typically generate operating cash flow equal to 5% to 15% of revenue.
How to use it: Operating cash flow is the single most important cash flow metric because it tells you whether your business sustains itself from daily operations. Positive operating cash flow means you can pay your bills, build reserves, and invest in growth without external financing. Negative operating cash flow means you are consuming cash faster than you generate it and will eventually run out unless the trend reverses. Track this monthly by comparing total bank deposits (excluding loan proceeds and owner contributions) against total operating payments. If the trend is declining over multiple months, investigate whether the cause is declining revenue, increasing costs, or worsening payment timing.
2. Cash Conversion Cycle (CCC)
What it measures: The number of days between when you pay for inventory and when you receive cash from selling it. A shorter CCC means cash cycles through your business faster, requiring less working capital to sustain operations.
Formula: Inventory days on hand + days sales outstanding minus days payable outstanding. Inventory days = (average inventory value / daily COGS). Days sales outstanding = (average accounts receivable / daily revenue). Days payable = (average accounts payable / daily COGS).
Benchmark: 30 to 60 days for most ecommerce businesses. Amazon FBA sellers with domestic suppliers can achieve 20 to 40 days. Businesses sourcing internationally with long lead times may run 60 to 90 days. Lower is better.
How to use it: The CCC reveals how efficiently your business converts inventory investment into cash. Improving CCC by 10 days on a business with $20,000 in monthly COGS frees up roughly $6,700 in working capital. Track CCC quarterly and work on each component: reduce inventory days through better forecasting and tighter reorder points, reduce receivable days through faster payment collection, and increase payable days by negotiating longer supplier terms.
3. Cash Burn Rate
What it measures: How much cash your business consumes per month during periods when outflows exceed inflows. Relevant during slow seasons, growth investment phases, or any period when the bank balance is declining.
Formula: (Starting cash balance minus ending cash balance) divided by number of months in the period. Only calculated for periods with net negative cash flow.
Benchmark: The burn rate itself has no universal benchmark because it depends on your business size and stage. What matters is the relationship between burn rate and cash reserves (which determines runway, described next). During normal operations, you should not be burning cash consistently. During planned investment periods (pre-season inventory buildup, new product launch, market expansion), a controlled burn is acceptable if it is budgeted and time-limited.
How to use it: Burn rate becomes critical when cash flow turns negative. If your cash balance dropped from $45,000 to $33,000 over three months, your burn rate is $4,000 per month. Combined with your current balance, this tells you how many months of runway you have. Monitor burn rate monthly during any period of negative cash flow and compare it to your forecast projections. If actual burn exceeds projected burn, investigate immediately rather than waiting to see if next month improves.
4. Cash Runway
What it measures: How many months your business can operate at the current burn rate before running out of cash. This is the most urgent metric during cash flow downturns or any period of negative operating cash flow.
Formula: Current cash balance divided by monthly burn rate. If your bank holds $33,000 and you are burning $4,000 per month, your runway is 8.25 months.
Benchmark: Minimum 3 months of runway at all times. Businesses with seasonal revenue should maintain 6 or more months of runway entering the slow season. If runway drops below 2 months, you are in crisis territory and need to take immediate action: cut discretionary spending, draw on credit lines, accelerate collections, or defer non-essential payments.
How to use it: Runway is your business survival clock. It tells you exactly how much time you have to fix a cash flow problem before the money runs out. Include runway in your weekly cash flow monitoring alongside your bank balance. When runway is comfortable (6 or more months), you can make strategic decisions without time pressure. When runway is tight (2 to 3 months), every spending decision should be evaluated through the lens of extending runway: does this expense generate cash within the runway window, or does it shorten the runway further?
5. Current Ratio
What it measures: Your ability to pay short-term obligations (bills due within the next 12 months) using your short-term assets (cash, inventory, receivables). This is a balance sheet metric that lenders use heavily when evaluating loan applications.
Formula: Current assets (cash + inventory + accounts receivable) divided by current liabilities (accounts payable + short-term loan payments + credit card balances + other amounts due within 12 months).
Benchmark: 1.5 to 2.0 is healthy. A current ratio below 1.0 means your short-term debts exceed your short-term assets, which is a solvency warning. Above 3.0 may indicate you are holding too much cash or inventory that could be deployed more productively. Lenders typically want to see a current ratio above 1.2 before approving loans or credit lines.
How to use it: Check your current ratio quarterly by pulling the numbers from your balance sheet (or calculating them from your bank balance, inventory value, receivables, and payables). If the ratio is declining over consecutive quarters, identify which component is driving the change: is cash decreasing, inventory growing, receivables aging, or payables increasing? Each cause has a different solution. Declining cash with stable liabilities suggests an operating cash flow problem. Growing payables with stable assets suggests you are stretching suppliers to cover other shortfalls, which creates supplier relationship risk.
6. Free Cash Flow
What it measures: The cash remaining after covering all operating expenses and capital investments. This is the cash available for debt repayment, reserves, owner compensation, and discretionary investments.
Formula: Operating cash flow minus capital expenditures (equipment purchases, warehouse improvements, and other long-term investments).
Benchmark: Positive free cash flow indicates a self-sustaining business that generates more cash than it consumes, including investment spending. Negative free cash flow during investment periods (new warehouse, major equipment purchase) is normal. Consistently negative free cash flow without corresponding investment means the business model is not generating enough cash to sustain itself.
How to use it: Free cash flow is the truest measure of how much money your business actually generates for you as the owner. Revenue looks exciting, profit looks healthy, but free cash flow is what hits your bank account after everything is paid. Track it quarterly and use the trend to decide how much you can afford to pay yourself, how much to allocate to reserves, and how much to reinvest in growth. If free cash flow is consistently positive and growing, your business is genuinely getting stronger. If it is stagnant despite revenue growth, your expenses are growing at the same rate as revenue, a sign that you need to focus on margin improvement and cost control.
7. Operating Expense Ratio
What it measures: Total operating expenses as a percentage of revenue, showing how efficiently your business converts revenue into cash before profit.
Formula: Total operating expenses divided by total revenue, multiplied by 100.
Benchmark: Varies by business model, but most profitable ecommerce businesses keep total operating expenses (including COGS) between 70% and 85% of revenue, leaving 15% to 30% as operating profit. If your expense ratio is above 90%, margins are too thin to generate meaningful cash flow, and even small revenue declines will push you into negative territory.
How to use it: Track the expense ratio monthly and watch for upward creep. A ratio that moves from 78% to 82% over six months means expenses are growing faster than revenue, slowly eroding your cash generation capacity. Break the ratio into components (COGS percentage, advertising percentage, overhead percentage) to identify which category is growing disproportionately. Our expense management guide provides a systematic approach to bringing each component back into target range.
Building Your Cash Flow Dashboard
You do not need to track all seven metrics every week. A practical cadence is: check your bank balance and operating cash flow weekly during your Monday financial review. Calculate burn rate and runway monthly (or weekly during cash-tight periods). Review current ratio, free cash flow, CCC, and expense ratio quarterly as part of a deeper financial health check. Most cash flow management tools and accounting platforms calculate several of these metrics automatically, and the ones that require manual calculation take only a few minutes once you know the formulas.