Reorder Quantity Calculator
How much to order, allowing for what is coming.
The number most often forgotten — and the usual cause of accidental overstock.
Order this quantity
350
rounded up to a multiple of 50
Forgetting the 200 units already in transit would mean ordering 200 too many.
How the Reorder Quantity Calculator works
Ordering back up to a target sounds simple until stock already in transit is forgotten — the single most common cause of accidental overstock. The right quantity is the target minus what you hold minus what is already coming.
Not financial advice. Marketplace fees change, and they vary by country, plan and seller status. Every rate here is an editable default, not a quoted price — check the platform's current fee schedule before you price a product against it. This is not tax or business advice.
Frequently asked questions
How is reorder quantity calculated?
Target stock level − current stock − stock on order + backorders owed. Targeting 800 with 250 on hand and 200 already in transit means ordering 350, not 550.
Why does stock on order get forgotten?
Because it is invisible in a physical count and often absent from simple spreadsheets. Ordering against on-hand quantity alone while a shipment is in transit is how a business ends up with double what it planned.
Should I round to supplier minimums?
Usually up to the nearest case or MOQ, provided the excess is a reasonable fraction of demand. Rounding up to a quantity that adds months of cover to chase a small discount is how overstock starts.
How does this relate to EOQ?
EOQ tells you the cost-optimal order size in the abstract. This tells you how much to order right now given your actual position. Use EOQ to set the target, this to place the order.