Plain definition
A rolling forecast is a forecast that is refreshed at a fixed cadence and extended so it always covers the same future horizon, such as the next twelve months. It is not a new annual budget every month. It replaces the closed period with actual results and adds a new period at the far end of the view.
Illustrative example
At the end of March, a company closes March actuals and updates its April–February forecast, keeping eleven forward months. It then adds March of the following year, preserving a twelve-month horizon. The revised view shows a planned equipment payment in the new March and a lower cash balance in the preceding February, when the deposit is due.
The chief executive can now decide whether to delay the purchase, change the payment terms, or arrange funding while the decision is still ahead. A calendar-year forecast ending in December would have hidden the payment until the next planning cycle.
Rolling forecasts work best when the horizon matches the decisions they support. A thirteen-week cash forecast and a twelve-month operating forecast can coexist because they answer different timing questions.
Why it matters
A fixed annual plan becomes less useful as its remaining months shrink. It may also push decisions just beyond year-end, where they disappear from discussion despite requiring cash or capacity soon after. The rolling horizon keeps attention on the next commitments rather than the administrative boundary of 31 December.
Practical consequence
Set the horizon, update date, cut-off for inputs, and the owners responsible for sales, staffing, costs, and funding assumptions. Lock the closed actual period, retain the prior forecast version for accuracy review, and explain material changes before adding the new end period. Do not use a rolling forecast to erase missed assumptions; its comparison with the prior version is what reveals where the process needs improvement.