To calculate trailing 12-month free cash flow, add the latest year-to-date figure to the previous full fiscal year, then subtract the previous year's matching year-to-date figure. Apply the same calculation separately to operating cash flow and capital expenditures, using a consistent definition.
The important detail is the period above each column. A cash-flow statement in a second- or third-quarter 10-Q commonly covers six or nine months. Treating that cumulative amount as a single quarter can produce a large error.
What does TTM free cash flow mean?
TTM means trailing twelve months: the latest twelve-month reporting window available. For a calendar-year company reporting through September 30, the window runs from October 1 of the previous year through September 30 of the current year.
This guide uses a simple cash-based definition:
Free cash flow = operating cash flow − cash capital expenditures
The SEC explains that free cash flow has no uniform definition and may leave mandatory cash obligations outside the calculation. Identify the company's reconciliation before comparing its number with another company's. SEC, Non-GAAP Financial Measures, Question 102.07
For the broader definitions and adjustments, see how to analyze free cash flow.
Step 1: Collect three matching periods
Find these columns in the latest annual and quarterly filings:
- The previous full fiscal year
- The current fiscal year to date
- The same fiscal year-to-date period from the previous year
For September results at a December-year-end company, that means the prior twelve-month year and two comparable nine-month periods. The latest 10-Q often includes both nine-month columns. Check for revisions or reclassifications before combining them with the annual filing.
The SEC's Financial Reporting Manual distinguishes year-to-date interim statements from the standalone-quarter income statements also presented in a 10-Q; standalone-quarter cash-flow statements are not generally required. Read the cash-flow statement's own headings rather than borrowing the income statement's dates. SEC Financial Reporting Manual, sections 1120 and 1320.1
Record the filing URL, period, currency, scale and exact line-item label for each input. Use the same entity and accounting basis throughout.
Step 2: Rebuild the twelve-month window
All figures below are invented for a fictional calendar-year business. Amounts are USD millions. Capital expenditures are shown as positive spending amounts.
Full year ended December 31, 2025:
- Operating cash flow: 900
- Cash capital expenditures: 300
- Calculated FCF: 600
Nine months ended September 30, 2026:
- Operating cash flow: 780
- Cash capital expenditures: 270
- Calculated FCF: 510
Nine months ended September 30, 2025:
- Operating cash flow: 620
- Cash capital expenditures: 200
- Calculated FCF: 420
Calculate the two components first:
TTM operating cash flow = 900 + 780 − 620 = 1,060
TTM cash capital expenditures = 300 + 270 − 200 = 370
TTM free cash flow = 1,060 − 370 = 690
You can cross-check the result directly:
TTM FCF = 600 + 510 − 420 = 690
The direct shortcut works only when all three FCF figures use the same definition. Starting with the separate components makes differences easier to spot.
Why does the formula work? Subtracting the first nine months of 2025 from the full 2025 year leaves its final quarter. Adding the first nine months of 2026 then gives October 2025 through September 2026, with no overlapping months.
Step 3: Avoid four common calculation errors
1. Adding cumulative quarterly statements together
Q1, half-year and nine-month cash-flow statements overlap. Adding them counts earlier months repeatedly. If you need the third quarter alone, subtract the first six months from the first nine months, using consistent figures.
2. Annualizing one quarter and calling it TTM
Multiplying a quarter by four creates an annualized run rate. It does not reconstruct twelve months of actual cash flow. Seasonal collections, inventory purchases and investment timing can make the two results very different.
3. Subtracting a negative capex number
If equipment purchases appear as (270), the outflow's magnitude is 270. Calculate 780 − 270 = 510. Subtracting −270 would incorrectly increase FCF. Keep your sign convention visible.
4. Reapplying adjustments already inside operating cash flow
Under the indirect method, operating cash flow already reflects the statement's noncash adjustments and working-capital movements. Do not add depreciation again or subtract the same working-capital increase twice. The SEC's financial-statement guide explains this reconciliation. SEC Beginners' Guide to Financial Statements
Step 4: Separate measured TTM from sustainable cash flow
A correctly assembled TTM figure is historical. It can still contain unusual tax timing, a working-capital release, temporarily low investment or other effects that need investigation.
Keep the calculated TTM figure and any normalized estimate in separate columns. Explain each adjustment and retain its source. Do not automatically remove every expense management calls unusual or every project described as growth investment.
Check whether cash capex omits relevant software spending or lease-funded investment. A changed fiscal year, a 53-week calendar, discontinued operations or a major acquisition can also require a more careful period comparison. Reconstruct the actual dates and basis instead of forcing the shortcut.
Step 5: Use the result in a clearly labeled yield calculation
Continue the fictional example with a current market capitalization of 10,000 million dollars:
Trailing cash-based FCF yield = 690 ÷ 10,000 = 6.90%
Price to FCF = 10,000 ÷ 690 = approximately 14.5x
Practice with the free FCF Yield Calculator: choose market capitalization, enter 690 as annual FCF and 10000 as market capitalization, and leave optional revenue blank. Both inputs use millions. Label this the unadjusted TTM case; make a separate normalized case if your analysis supports adjustments.
A current market value and trailing cash-flow period serve different roles. Record both dates. This yield is an equity-oriented screening approximation, not a dividend yield, promised return or complete measure of cash distributable to shareholders.
Before moving to a reverse DCF
Stock Metric Lab's Reverse DCF Calculator requires normalized free cash flow to the firm, or FCFF. TTM describes a period; it does not convert operating cash flow minus capex into FCFF.
FCFF measures operating cash flow after operating taxes and reinvestment, before debt payments. Financing, tax and reinvestment treatment must match the model. See Damodaran's cash-flow framework and our reported FCF-to-DCF example before transferring a real company's figures.
Start with the dates, verify the arithmetic, then examine the economics. A precise twelve-month total is a useful foundation for the next question: how much of that cash generation can reasonably persist?
Educational content only. All numerical examples are fictional. This article does not recommend buying or selling any security.