The complete run rate and seasonal index calculation on one company's twelve months of revenue, small enough to check by hand: the trailing three-month run rate at four points in the year and how far each is from the actual year, the seasonal index per month from three years' shares, the deseasonalized run rate, the same-period-last-year comparison, and the one-off order that doubles a quarter, so a reader can reproduce every figure and then run it on their own ledger.
Run rate is the simplest projection and the easiest to get wrong in a seasonal business. On twelve months it can be checked by hand. This page works the run rate at four points, the seasonal index, the deseasonalized figure, the year-on-year comparison and the one-off order.
| Month | Revenue | Share of year |
|---|---|---|
| Jan | $0.85m | 5.3% |
| Feb | $0.95m | 5.9% |
| Mar | $1.20m | 7.5% |
| Apr | $1.05m | 6.6% |
| May | $1.15m | 7.2% |
| Jun | $1.20m | 7.5% |
| Jul | $1.90m | 11.9% |
| Aug | $1.30m | 8.1% |
| Sep | $0.90m | 5.6% |
| Oct | $1.50m | 9.4% |
| Nov | $1.80m | 11.3% |
| Dec | $2.20m | 13.8% |
| Year | $16.00m | 100% |
Run rate = trailing three months × 4
| Computed after | Trailing three | Annualized | Against the actual year |
|---|---|---|---|
| March | $3.00m | $12.0m | 25% under |
| June | $3.40m | $13.6m | 15% under |
| September | $4.10m | $16.4m | 3% over |
| December | $5.50m | $22.0m | 38% over |
Four run rates, four answers, one year.
From three years' monthly shares, averaged; index = share ÷ 8.33%.
| Month | Average share | Index |
|---|---|---|
| Jan | 5.1% | 0.61 |
| Feb | 5.8% | 0.70 |
| Mar | 7.3% | 0.88 |
| Apr | 6.5% | 0.78 |
| May | 7.0% | 0.84 |
| Jun | 7.5% | 0.90 |
| Jul | 12.0% | 1.44 |
| Aug | 8.0% | 0.96 |
| Sep | 5.6% | 0.67 |
| Oct | 9.2% | 1.10 |
| Nov | 11.5% | 1.38 |
| Dec | 14.5% | 1.74 |
Deseasonalized = trailing three ÷ (sum of the three months' indexes ÷ 3) × 4
| Computed after | Trailing three | Mean index | Deseasonalized | Annualized |
|---|---|---|---|---|
| March | $3.00m | 0.73 | $4.11m | $16.4m |
| June | $3.40m | 0.84 | $4.05m | $16.2m |
| September | $4.10m | 1.02 | $4.02m | $16.1m |
| December | $5.50m | 1.41 | $3.90m | $15.6m |
Four figures within five percent of the year, from every quarter.
| Quarter | This year | Last year | Growth |
|---|---|---|---|
| Q1 | $3.00m | $2.80m | +7% |
| Q4 | $5.50m | $5.30m | +4% |
No index needed; the growth is the comparison.
Account 4471's March order: $900,000 against a median order of $40,000. Flagged.
| Run rate after March | With the order | Without |
|---|---|---|
| Trailing three | $3.00m | $2.10m |
| Annualized | $12.0m | $8.4m |
| Deseasonalized, annualized | $16.4m | $11.5m |
The order is real and in the ledger. For ranking and projection, the figure without it is the one, and the row says so.
Q4 annualized in January. A budget a third too high.
Index from a benchmark. Somebody else's December.
One-off unflagged. Q1's deseasonalized figure overstated by five million.
Comparison unstated. Raw, indexed and year-on-year on one chart.
The same index per segment and per account with its own season, the same one-off flag from each account's median. Covirage runs it on the ledger every month. The run rate guide covers the traps, and the seasonality guide covers the index at scale.
Because Q4 carries 37 percent of the year's revenue and annualizing it assumes every quarter looks like it. The index says Q4's months run at 1.4 to 1.5 times an average month, and dividing by that brings the run rate back to the year.
Same period last year, because it needs no index and everyone understands it. The index is for a new account or product with no prior year, or when the in-year trend matters. Both are shown here.
Flagged from the account's own history, a $900,000 order against a median order of $40,000, and shown with and without. The run rate without it is the one that ranks; the ledger keeps the order.