Lead-time demand
180 units
Free calculator
Type your average daily sales, lead time, and safety stock. Your reorder point updates live. No email, no gate, nothing leaves this page.
The calculator
The boxes start filled with an illustrative example, not a benchmark. Replace it with your own numbers.
How long it takes from placing an order with your supplier to having it ready to sell.
Your buffer against a slow week or a late shipment. Use the safety stock calculator if you don't already have this number.
Reorder point
Order more once you hit 225 units on hand. That's 180 units to cover the 12-day lead time, plus 45 units of safety stock in case sales pick up or the shipment runs late.
lead-time demand = average daily sales * lead time reorder point = lead-time demand + safety stock reorder point, days = reorder point / average daily sales
This is a planning baseline, not a live forecast. It tells you the level that should trigger your next order given a steady average, nothing more.
See it on your own data Real numbers from your Shopify store, not a guess.
This assumes average daily sales stays flat for the entire lead-time window. A seasonal spike, a promotion, or a slow week during that window makes the real answer wrong in either direction: too low a reorder point during a spike means a stockout, too high during a slow stretch means cash tied up in inventory that sits.
Treat this as a planning baseline you revisit as conditions change, not a demand forecast that stays correct on its own.
Questions
The inventory level that should trigger placing your next order. It's set high enough that, given your normal lead time, you don't run out before the new stock arrives, plus a buffer for the unexpected.
Safety stock is one input into the reorder point, not a separate trigger. Reorder point covers two things added together: the demand you expect to see during the lead time, plus the safety stock buffer on top of it. They're related but not the same number.
Directly and linearly: a longer lead time means more demand happens before the new order arrives, so the trigger point has to sit higher. Doubling lead time roughly doubles the lead-time-demand portion of the formula.
This is a real limitation of the formula above. It assumes a flat average daily sales rate through the whole lead-time window, which breaks down around a seasonal peak or trough. Recalculating with a seasonally adjusted daily sales figure is a reasonable workaround, but it's still an approximation, not a forecast.
Different questions. Reorder point answers when to order. Economic order quantity (EOQ) answers how much to order once you do. They're usually used together, not as alternatives to each other.
Next
Upstream tracks average daily sales and lead time per SKU from your own store data, and keeps reorder points current as sales patterns shift, not a snapshot from the day you typed it in.