What is a rolling forecast, and does it replace the annual budget?
A rolling forecast brings actuals into the model every month and re-forecasts the remaining period with up-to-date information. It does not replace the budget; it makes visible the gap between what the budget says and where the company is actually heading.
A rolling forecast is a planning method in which the company’s financial outlook is updated at regular intervals, usually monthly, in the light of actual results and new information. “Rolling” refers to the horizon moving forward one period with each update: a forecast made at the end of January covers February to January, one made at the end of February covers March to February.
Budget versus rolling forecast
| Annual budget | Rolling forecast | |
|---|---|---|
| Purpose | Target and commitment | Current expectation |
| Frequency | Once a year | Monthly or quarterly |
| Horizon | Calendar year | Fixed length (e.g. 12 months), always moving forward |
| Detail | High | Lower; driver-based |
| Use | Measuring performance | Taking decisions in time |
A budget tied to the calendar year sees less and less as the year goes on: in October it shows only three months ahead. A rolling forecast always offers a horizon of the same length.
Does a rolling forecast replace the budget?
For most companies, no. The budget is management’s commitment at the start of the period; performance and incentive systems are usually tied to it. The rolling forecast answers “where will we end up on the current course?” The real management agenda is the gap between the two: why is the distance between target and expectation opening up, and what will it take to close it?
Some companies gradually simplify the annual budget and shift weight to the rolling forecast. That choice depends on the organisation’s maturity and planning culture.
How do you set one up?
- Identify the drivers. A rolling forecast does not forecast every line separately; it focuses on the few drivers that move the result most: sales volume, price, gross margin, headcount, collection period. I explain the logic of the driver-based approach in Why a budget is not a spreadsheet.
- Fix the horizon. Twelve or eighteen months are common choices. The first few months can be monthly, the rest quarterly.
- Tie the calendar to the close. The forecast should be updated right after the monthly close, which makes a fast monthly close a precondition.
- Assign owners. The sales forecast should come from sales and the cost forecast from operations; finance brings them together and tests their consistency.
- Track forecast accuracy. Comparing past forecasts with actuals shows which driver is consistently misjudged.
Common mistakes
- Rebuilding the budget every month: a rolling forecast prepared in as much detail as the budget becomes unsustainable.
- Setting the forecast equal to the target: the forecast should show the expected outcome, not the desired one. A forecast kept equal to the target loses its warning function.
- Forgetting cash: the cash forecast must be updated as well as the profit forecast; for the short term a 13-week cash flow does this job.
You can see how a rolling forecast runs alongside the budget in the Budget & Forecast Management Model. For the general framework, see the FP&A page.
Frequently asked questions
How often should a rolling forecast be updated?
Monthly updates are enough for most companies. In fast-changing environments or under cash pressure, the short-term part can be updated weekly.
Can small companies use a rolling forecast?
Yes. A simple model built on a few drivers lets small companies correct course during the year too.