Free cash flow conversion measures how much of a company's accounting profit shows up as cash left over once the business has paid for the equipment, buildings and infrastructure it needs to keep running. A business can report rising net income while its cash generation moves the other way, and Microsoft Corporation's most recent twelve months of filings show exactly that split.
The idea in plain words
Net income is an accounting figure. It includes non-cash items such as depreciation, and it says nothing about how much cash a company actually spent buying new servers, warehouses or production lines. Free cash flow conversion asks a simpler question: once the business has paid its operating costs and funded the capital spending it needs to keep running, how much cash is actually left? A company whose free cash flow tracks its net income closely is converting profit into cash efficiently. One where the two series pull apart, as Microsoft's have, is worth a closer look.
The free cash flow formula, step by step
The free cash flow formula has two steps. First, take operating cash flow: the cash a business generates from running its core activities, found on the cash flow statement rather than the income statement. Second, subtract capital expenditure: the cash spent buying or building long-lived assets such as data centres, equipment or property. What remains after those two steps is free cash flow, the cash a company could in principle return to shareholders, use to pay down debt, or hold, without touching its day-to-day operations or its reinvestment needs. Dividing free cash flow by revenue produces the free cash flow margin, a measure of how many cents of spendable cash each dollar of sales throws off.
A worked case: Microsoft's filings
Over the twelve months covered by Microsoft's latest quarterly filing, operating cash flow reached $182.9 billion, up 34.4% from the year before. Capital expenditure absorbed $115.9 billion of that, having risen 79.6% year over year and now equal to 34.9% of revenue of $331.8 billion. What remained, free cash flow, came to $67.0 billion, down 6.5% from the prior year, even as net income rose 31.3% to $133.7 billion.
The gap shows up directly in the margins. Microsoft's net margin reached 40.3% of revenue, while its free cash flow margin stood at 20.2%, down 5.2 percentage points from a year earlier and below the company's own previous low of 22.9% in its recorded history. Operating cash flow kept growing; it was the capital spending line that pulled free cash flow down.
The same divergence changes how far profit stretches toward shareholder payments. Dividends paid absorbed 19.8% of net income over the period but 39.5% of free cash flow: the same cash outlay looks far larger once set against cash actually generated rather than profit reported.
| Measure (TTM) | Value | YoY change |
|---|---|---|
| Operating cash flow | $182.9bn | +34.4% |
| Capital expenditure | $115.9bn | +79.6% |
| Free cash flow | $67.0bn | −6.5% |
| Free cash flow margin | 20.2% | −5.2pp |
| Net income | $133.7bn | +31.3% |
Reading margin against yield
Free cash flow margin and free cash flow yield answer different questions, and conflating them is a common source of confusion. Margin divides free cash flow by revenue: it shows how efficiently a business turns sales into spendable cash, independent of anything happening in the market. Yield divides free cash flow by a company's market value: it shows how much cash flow is on offer for the price paid, and it moves with the share price even when nothing about the underlying business changes. This article works from filed figures only, so no yield figure appears here; it needs a price input this analysis deliberately does not use.
Common mistakes and limits
A single quarter's free cash flow can swing sharply on working-capital timing alone. A large customer paying a week late, or a supplier being paid early, can move the figure without reflecting the health of the business. A trailing twelve-month figure, as used above, smooths some of that noise but not all of it, particularly around large one-off capital projects.
A rising capex figure is not automatically a warning sign. Microsoft's capital expenditure rose 79.6% over the period, the direct cause of its lower free cash flow margin. The stronger alternative reading is that this reflects a deliberate, large-scale infrastructure build that depresses the margin now and may lift operating cash flow and revenue in later periods. The filings reviewed here do not say when, or whether, that reverses.
Comparing conversion across different companies carries its own traps. Differences in depreciation schedules, lease accounting and the treatment of stock-based compensation can make two businesses' free cash flow margins look different for reasons that have nothing to do with how well each converts profit into cash.
Where to see it on Fundamentalytics
Fundamentalytics tracks free cash flow margin across covered companies on the cash conversion ranking at /indices/cash-conversion/, where moves like Microsoft's sit alongside peers reporting the same period. The assumptions behind how free cash flow is used in our valuation models, including the treatment of stock-based compensation and interest, are set out at /valuation-methodology/.
What it means for value
In our model of Microsoft, the base case assumes stage-one growth of 17.8%. If the past year's fall in free cash flow margin, 5.2 percentage points, persisted at current revenue, model value falls 19.8% under the stated assumptions; each single percentage point of lower margin on its own moves model value down 4.7%. Growth carries its own weight in the model: five percentage points less growth than the base case drops model value 23.7%, and five points more lifts it 30.4%. Margin and growth both matter here, and the model treats a one-year margin move and a multi-year growth change as separate inputs rather than directly comparable figures. These are model values under stated assumptions, not a comparison with the share price.
