YoY, QoQ and TTM: how to compare company results without mixing periods
YoY compares a period with a year earlier. QoQ compares consecutive quarters. TTM combines the latest twelve months. Each answers a different question.
A company can report strong year-on-year growth, a fall from the previous quarter and record twelve-month revenue at the same time. Before deciding which headline describes the business, check the dates behind it.
Reviewed 20 September 2026
Start with the question you want answered
| Comparison | What you compare | Useful question | Main limitation |
|---|---|---|---|
| Year on year, or YoY | A period with the equivalent period a year earlier | Is the business larger than at the same point last year? | An unusually weak or strong starting period can distort growth |
| Quarter on quarter, or QoQ | One quarter with the preceding quarter | What changed recently? | Seasonal patterns can dominate the result |
| Trailing twelve months, or TTM | The latest four quarters for a quarterly reporter | What did the business produce over the latest full-year window? | It can hide a recent turn because older quarters remain included |
Keep fiscal dates beside the labels. A company's first quarter need not end in March. A retailer's 53-week year can also make a comparison less straightforward than its heading suggests.
One fictional company, three accurate readings
Imagine a retailer with revenue of $80.000 million in last year's first quarter, $150.000 million in its recent holiday quarter and $100.000 million in this year's first quarter.
Year-on-year growth is ($100.000 million ÷ $80.000 million − 1) × 100 = 25%. Quarter-on-quarter growth is ($100.000 million ÷ $150.000 million − 1) × 100 = −33.333%.
Both calculations are correct. The seasonal decline does not erase the year-on-year increase. Equally, the increase does not prove demand is accelerating: you still need comparable earlier quarters, prices, volumes and management's explanation.
Suppose the latest four quarters are $100.000 million, $110.000 million, $140.000 million and $150.000 million. Their sum is TTM revenue of $500.000 million. These are invented figures, not a report about a listed company.
Calculate TTM without counting a quarter twice
If the latest annual report is followed by a half-year update, a useful construction is: latest annual total + current half-year total − prior-year half-year total. The subtraction removes the older months that the new period replaces.
For example, $480.000 million + $210.000 million − $190.000 million = $500.000 million. Adding the new half-year to the annual figure without subtracting the old one would produce an eighteen-month total.
This method requires matching definitions and scope. An acquisition, disposal, restatement or change of reporting currency may require further adjustments. Keep an explanation of any adjustment beside the calculation.
Watch cumulative cash-flow statements
A second-quarter cash-flow statement may report six months, while its income statement also shows a standalone three-month column. Do not compare six months of operating cash flow with three months of revenue and call the result a quarterly margin.
Where the accounting basis is consistent, subtract the first-quarter cumulative figure from the first-half cumulative figure to derive the second quarter. If first-half operating cash flow is $30.000 million and the first quarter contributed $12.000 million, the derived second quarter is $18.000 million. Label it as a calculation from the two reports.
The SEC report-reading guide is a useful map to the financial statements and supporting notes. Always read the column headers in the actual report.
Do not add or average every metric
Revenue and operating profit can be summed across non-overlapping periods on a consistent basis. A balance-sheet cash balance is a snapshot: adding four quarter-end cash balances does not produce annual cash.
Margins also need care. A quarter with $1.000 million of profit on $10.000 million of revenue has a 10% margin. Another with $9.000 million on $30.000 million has a 30% margin. Combined, profit of $10.000 million divided by revenue of $40.000 million gives 25%, not the simple average of 20%.
In Helmbeam's Numbers view, check whether you selected quarterly or trailing figures before comparing revenue, EPS, margins or cash flow. Keep the same basis when you move to the filing. For a wider report review, use the earnings checklist.
Sources
2 referencesFrequently asked questions
Is TTM the same as the last financial year?
Only when the latest twelve-month window ends on the financial year end. After a new quarter, TTM includes newer months and removes the corresponding older months.
Is YoY better than QoQ?
Neither replaces the other. YoY helps compare equivalent seasonal periods; QoQ highlights recent changes but may be dominated by seasonality. Read both with their dates.
Can I average quarterly margins to get an annual margin?
A simple average can be misleading when quarterly revenue differs. Add the relevant profit figures and divide by the corresponding total revenue on a consistent basis.
Helmbeam is a research and analysis tool operated by Scydex Ltd. Scydex Ltd is not authorised or regulated by the Financial Conduct Authority. Helmbeam does not provide investment advice, recommendations, or solicitations to buy or sell securities. All data is for informational purposes only. Past performance of any signal, cohort, or classification does not guarantee future results. All investing involves risk, including loss of principal. Always conduct your own research and consult a qualified financial adviser before making investment decisions.
Keep the reporting basis with the question
Open a company in Helmbeam on iPhone or Android, choose a reporting basis in Numbers and check the same period in its filing. Every stock is a research opportunity; active setups are the subset whose current structure qualifies. Follow a company when you have a question worth revisiting.
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