Revenue Seasonality Adjustment Calculator

Revenue seasonality confuses. This calculator normalizes.

Reported monthly revenue

Seasonal index (1.0 avg)

Prior year same month

Seasonally-adjusted revenue

$329,412

YoY growth % (adjusted)

4.48%

Raw YoY growth %

4.48%

How the math works

Adjusted = reported / seasonal index. Compare month-to-prior-year on both bases.

Raw reported $280k × 1/0.85 = $329k adjusted. Prior year same month $268k adjusted to $315k. Trends well (both up). Seasonality explains apparent monthly variation.

How to Use

Enter reported monthly revenue.
Enter seasonal index (1.0 = average).
Enter prior year same month.
Read seasonally-adjusted revenue.

Frequently Asked Questions

Seasonal indices?

Multifamily: Sept-Oct highest (move-ins), Jan-Feb lowest. Hotel: varies widely by market/type. Retail: Nov-Dec spike (holidays). Industrial: mostly flat. Compute by dividing each month's average by annual average. Use 3+ years of history.

Why adjust?

Un-adjusted monthly tells noise. Seasonally-adjusted reveals trend. January down 15% vs December could be: (a) normal seasonality, (b) deterioration. Adjusted data separates. Lending/investing decisions require adjusted view.

Pro forma application?

Forecast by month using seasonal indices. Don't straight-line annual revenue / 12. Seasonal pattern produces 15-40% swings by month on hotel/hospitality. Modest for multifamily (5-15%). Factor into cash flow timing and covenant testing.

What does competitive benchmarking look like?

Pull 3-5 comparable properties or units in your submarket from CoStar, Yardi, CIM, or your local broker. Normalize by unit type, class, and age. Your outputs should fall within one standard deviation of the comp-set mean. Outliers are either opportunities or warning signs — dig into why. Monthly benchmarking keeps your portfolio on-market and pricing sharp.