The TTM calculator above rolls the last four reported quarters into a single twelve-month figure. It offers the two routes people actually use: the annual-plus-year-to-date shortcut, which needs only three numbers off published statements, and a direct sum of four quarters when you have them individually. It then shows how that rolling figure compares with the last completed fiscal year, and what it works out to per share.
Arb Digital builds free calculators that are explicit about what a number means. TTM exists to solve a specific problem — that the most recent audited annual figure can be nearly a year out of date by the time you look at it — and it solves that problem while introducing a few of its own, which the second half of this page is about.
What This TTM Calculator Does
It computes the trailing twelve month total for any additive measure: revenue, net income, EBITDA, free cash flow, operating expenses. The measure has to be a flow over a period rather than a balance at a point — you can roll twelve months of revenue, but rolling twelve months of total assets is meaningless, because a balance sheet item already describes a single instant.
Alongside the headline, the grid gives growth against the last full fiscal year, which is the cleanest way to see whether the rolling window is above or below the last audited annual number; year-to-date growth, which isolates how the current partial year is running against the same stretch last year; the per-share figure; and the average quarter within the window.
Two boundaries with live tools. Our sales growth calculator compares two periods and reports the change between them; it does not roll anything, and comparing a partial year against a full one there is a classic misuse this page exists to avoid. Our CAGR calculator annualises growth across several years, which is a different question again. And the moving average calculator is the general form of what TTM is: a rolling window applied to a series.
How to Use It
- Choose the arrangement that matches your source data. Annual reports and interims give you the year-to-date route; a data provider or a quarterly history gives you the four-quarter route.
- For the year-to-date route, enter the last completed fiscal year, the current year to date, and the same point in the prior year. Check that the two year-to-date figures cover the same number of months.
- For the four-quarter route, enter the four most recent quarters on a consistent basis.
- Enter a share count in the same units if you want a per-share figure, using a weighted average diluted count to line up with reported numbers.
- Read the growth against the last full year. That is the comparison the rolling window is designed to support.
The Formula and How It Is Calculated
The rolling identity is:
TTM = Last full fiscal year + Year-to-date this year − Year-to-date same period last year
which is exactly equal to the sum of the last four quarters, and the reason it works is worth seeing. Adding the current year to date brings in the recent months; subtracting the prior-year equivalent removes the same months from the old fiscal year, so the window ends up twelve months long and ending at the latest report date.
Work through the defaults. A last full year of 480, nine months of the current year at 390, and the same nine months last year at 350 gives 480 + 390 − 350 = 520. Against the last full year of 480, that is growth of 40 ÷ 480 = 8.33 per cent. The year-to-date comparison, 390 against 350, is 11.43 per cent — a faster rate, which tells you the recent months are running ahead of the twelve-month average and are pulling it up.
Across 40 shares the TTM figure is 520 ÷ 40 = 13.00 per share, and the average quarter in the window is 520 ÷ 4 = 130.00. The four-quarter route reaches the same kind of answer by direct addition: 140 + 130 + 120 + 130 = 520.
Why a Rolling Window Beats an Annual Figure
The problem TTM solves is staleness. A fiscal year that ended in December is not usually reported until well into the following year, and by the time the third quarter of the next year is published that annual figure describes a period that ended fifteen months ago. Any ratio built on it — a price multiple, a margin, a coverage ratio — is describing an old company.
The obvious alternative, annualising the current year to date by scaling it up, is worse. Multiplying nine months by four thirds assumes the missing quarter looks like the average of the first three, which for any business with a seasonal pattern is simply false. A retailer annualised from its first three quarters will look far weaker than it is; annualised from a fourth-quarter run rate, absurdly stronger.
TTM avoids both traps because it always contains exactly one of each quarter. Whatever the seasonal pattern, every twelve-month window includes the same four seasons, so comparisons between consecutive windows are seasonally clean. That property is why TTM is the standard denominator for multiples and the standard basis for covenant tests. In the United States, the interim reporting that makes it possible is the quarterly Form 10-Q, and the form and content of the financial statements filed with the SEC are governed by Regulation S-X, whose scope is set out at 17 CFR § 210.1-01.
Where TTM Misleads
Four failure modes are worth knowing, because none of them announces itself.
The first is that quarterly figures are usually unaudited while the annual is not. A TTM built from three unaudited quarters and part of an audited year is a hybrid, and a later restatement can move it. If a figure matters, check whether the underlying quarters have since been revised.
The second is one-off items. A rolling window carries a large disposal gain, impairment, legal settlement or restructuring charge for a full four quarters and then drops it abruptly, producing an apparent change in the business that is really just the item ageing out of the window. Anyone reading a sudden TTM movement should first ask what left the window rather than what happened in the quarter.
The third is corporate actions. An acquisition part-way through the window means the TTM figure includes the acquired business for only part of the period, so it is neither the old company nor the new one. Divestitures do the same in reverse, and share counts changed by buybacks or issuance make the per-share figure a blend of two capital structures. Our EPS calculator and P/E ratio calculator are the places to work through the per-share consequences carefully.
The fourth is definitional drift. If a company changes how it reports a segment, adopts a new accounting standard, or changes its fiscal year end, the quarters inside the window are no longer measured the same way. TTM adds them anyway, because addition does not check its inputs. This is the failure most likely to survive into a published analysis unnoticed.
Choosing the Right Route to the Number
The two methods on this page are arithmetically equivalent and fail differently in practice.
The annual-plus-year-to-date route uses fewer numbers, all of them from published statements, and it is generally the more robust for that reason. Its one failure mode is a mismatch between the two year-to-date periods — nine months against six, or a 52/53-week retail calendar where one year has an extra week. That mismatch produces a wrong answer with no visible symptom, which is why the field hint on this page insists on the check.
The four-quarter route is more transparent, because you can see each quarter and spot the odd one. It requires four figures on a consistent basis, which is harder than it sounds when a company has restated, changed segments or reported a stub period. It is the better route when you already have a clean quarterly history and want to see the shape as well as the total.
Either way, the result is a description of the past. It is not a run rate and not a forecast, and treating a rising TTM as a projection is the most common misuse of it. If forward numbers are what you actually need, our revenue forecast calculator is built for that, and the free cash flow calculator and EBITDA calculator produce measures that TTM is frequently applied to.
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Browse the Free Tools Hub Talk to Arb DigitalCommon Mistakes to Avoid
- Mismatching the two year-to-date periods. Nine months against six removes the wrong stretch of time, and the answer looks perfectly plausible.
- Rolling a balance sheet item. TTM works on flows over a period. A balance at a point in time is already an instant and cannot be summed across quarters.
- Annualising year-to-date instead. Scaling nine months up by four thirds assumes the missing quarter is average, which seasonality makes false for most businesses.
- Reading a TTM change as a business change. A one-off item ageing out of the window moves the figure without anything happening in the current quarter.
- Treating it as a forecast. A trailing window describes twelve months that are over. It carries no prediction of the next four quarters.
Related Free Tools From Arb Digital
For growth between two periods use the sales growth calculator, and the CAGR calculator to annualise across several years. The moving average calculator is the general rolling-window form, while the EBITDA calculator and free cash flow calculator build measures that TTM is often applied to, and the EPS calculator and P/E ratio calculator handle the per-share side. For forward figures rather than trailing ones, use the revenue forecast calculator. Everything else is on the free online tools hub.
Frequently Asked Questions
Trailing twelve months: the total of a financial measure over the most recent twelve-month period ending at the latest reporting date, rather than over a fiscal year. It is used because a fiscal year figure can be a year or more out of date by the time it is being read, while a rolling window always ends at the last report.
Add the last completed fiscal year to the current year-to-date figure, then subtract the year-to-date figure for the same point in the prior year. Adding the recent months and removing the equivalent old ones leaves a window exactly twelve months long. It is arithmetically identical to summing the four most recent quarters.
Only immediately after a year end, when the two windows coincide. At any other point the TTM window has moved forward by one or more quarters, so it contains recent months the fiscal year does not and excludes old ones it does. That difference is the whole reason for using it.
No. TTM sums a flow measured over a period, such as revenue, net income or cash flow. A balance sheet item is a position at a single instant, so adding four of them produces a number with no meaning. Where a ratio needs both, the usual convention is a period flow over an average balance.
Because scaling a partial year up assumes the remaining months resemble the average of those already reported, which seasonality makes false for most businesses. A trailing twelve-month window contains exactly one of each quarter regardless of the seasonal pattern, which is what makes consecutive windows comparable.
Most often because a one-off item has aged out of the rolling window. A large gain or charge stays in the figure for four quarters and then drops out abruptly, moving the total without anything having changed in the current quarter. Check what left the window before interpreting the movement.
Usually only in part. Interim quarterly statements are typically unaudited while annual statements are audited, so a trailing figure built from recent quarters is a hybrid and can move if those quarters are later restated. Where the number matters, check whether the underlying periods have been revised.
No. It is a description of a period that has already ended, and it carries no forecast. Using it as a run rate assumes the business, its seasonality and its one-off items all continue unchanged, which is an assumption you have to make separately and defend on its own terms.
This page performs arithmetic on figures you enter. It is not financial advice, not a valuation and not a recommendation about any security. Reported figures may be unaudited or subsequently restated, and accounting policies, corporate actions and one-off items all affect what a trailing twelve-month total means.
