Demand forecasting
Demand Spike
By the Supply Chain Manager team · Updated October 16, 2026
A demand spike is a short burst of sales far above a SKU's usual rate, either a real rise in demand or a single unusually large order.
The two cases need opposite responses. A sustained rise means future forecasts and reorder points should go up. A single bulk order is a one-off: reacting to it as a trend leads to overstock once it passes.
A useful test is to remove the biggest single day and check whether the week is still unusual. If it is not, the spike was one order.
Demand spike example
Illustrative numbers: a SKU usually sells 10 a day. One week it sells 370, and 310 of that came on one day with a single 300-unit order. The other six days total 60 units, a normal pace, so this was a one-off order rather than rising demand.
Why demand spike matters for distributors
Distributors see large one-off orders all the time: project work, stock-ups and new accounts. Separating them from genuine trend changes protects both availability and cash.
Common demand spike mistakes
- Feeding a one-off bulk order into the average and inflating future orders.
- Flagging normal lumps on intermittent SKUs as spikes.
Demand spike in Supply Chain Manager
Supply Chain Manager flags a spike when the last 7 days run at least three times the usual rate and more than three standard deviations above it, and labels whether it looks sustained or like a single large order.
Open the live demoExamples on this page use made-up round numbers to show the calculation. They are not benchmarks or results from real businesses.