Key Idea: A sales forecast is an estimate of future sales, and almost every plan in a business starts from one. This topic is why businesses forecast, how a trend is read from data, and why forecasts go wrong.
Why forecast
- Plan staff, stock, capacity and cash before the sales arrive.
- Set targets and budgets, and judge big decisions such as a new shop.
- Compare forecast with actual sales and learn from the gap.
Forecasting from data
- Read the trend in past sales and extend it (extrapolation).
- Simple linear regression: a line of best fit linking sales to one other figure.
- Correlation shows how closely two figures move; it does not prove cause.
Limits
- A forecast assumes the past will repeat; new rivals or a recession break that.
- It is only as good as its data and the people who make it.
- The further ahead, the less reliable: use a range and review it.
The words to know
| Word | Means | Do not confuse with |
|---|---|---|
| Sales forecast | an estimate of a business's future sales over a given period | a sales target, which is what the business aims for |
| Trend | the general direction of sales over time | one good or bad month |
| Extrapolation | extending a trend line beyond the data to predict future values | reading a value inside the data |
| Simple linear regression | a line of best fit showing how one variable changes with another | correlation, which only measures how closely they move |
| Correlation | how closely two variables move together | causation: one does not have to cause the other |
Name the benefit or limitation, then show it in the case: which decision the forecast feeds, or which change could make it wrong. For a Discuss, weigh how useful the forecast is against how far it can be trusted, then decide.
Exam-style question
Lena's Bakery Ltd forecasts that its new Station Road shop will sell 250 loaves a day from September 2026, and that Mill Lane will need to bake 1,450 loaves a night. Explain one advantage of sales forecasting for Lena's Bakery Ltd.
Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Important: A forecast is an estimate built on assumptions. Say what could make it wrong in this case: a new rival, a change in the economy, too little data. And correlation is not cause: two figures can rise together without one driving the other.
Tap each card to check yourself.
Name two things a bakery plans from a sales forecast. Any two: staff and shifts, flour and ingredients, oven capacity, cash flow, the budget.
Marco forecast 420 loaves a day at Market Square; 390 were sold. What should he do? Find the reason for the gap (Goldcrust's cheaper loaves nearby) and use it in the next forecast.
What does extrapolation assume? That the past trend carries on unchanged into the future.
Sales and radio adverts both rose before Christmas. Did the adverts cause the sales? Not necessarily. Christmas raised both; correlation does not prove cause.
Why is a forecast for a brand-new shop less reliable? There are no past sales to build on, so it rests on assumptions and research.
How can a business reduce the risk of a wrong forecast? Use a range (low and high), plan for the low case, and review the forecast every month.
Exam tips
- Tie each benefit to a decision the forecast feeds: staff, stock, capacity or cash.
- Tie each limitation to something in the case that could change.
- A trend line extended beyond the data is extrapolation, and less reliable the further it goes.
- Correlation is not cause.
- In a Discuss, weigh usefulness against reliability, then decide.