Demand Forecasting
Demand forecasting is the practice of estimating future unit sales by SKU, channel, and time period, using sales history, seasonality, promotions, and known events such as launches.
Why it matters for ecommerce brands
Every purchase order, safety stock level, and 3PL capacity booking starts from the forecast. Forecast errors turn directly into stockouts or overstock.
Common questions
- How far ahead should an ecommerce brand forecast demand?
- At least as far as your longest replenishment lead time plus one order cycle, so you can place purchase orders in time. Brands importing from Asia often forecast 6 to 12 months out at a monthly level and refine the nearer weeks in more detail.
Cite this entry
"Demand Forecasting." Fulfillment Lexicon, last reviewed October 16, 2026. https://fulfillment.wiki/glossary/demand-forecasting/