When to reorder inventory. The Reorder Point Calculator takes average daily sales (units), supplier lead time, safety stock (units) and returns reorder point (units) plus demand during lead time. Results update as you type, and the formula is shown under the result so you can repeat it in your own spreadsheet.
Online and retail margins are decided by the costs that are easy to forget: fees, shipping, returns, storage and advertising. Fill in every line, even with an estimate, before deciding what to sell and at what price. Use the worked example below to check the maths against your own figures.
How the Reorder Point Calculator works
When stock falls to the reorder point, order. The lead-time demand covers sales while you wait; the safety stock covers surprises.
Worked example
With the example values (average daily sales (units) of 40, supplier lead time of 8 days, safety stock (units) of 160), the reorder point (units) is 480; demand during lead time 320. Change any figure above and the result updates immediately; use Copy results to paste the summary into a note or email.
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Frequently Asked Questions
How is reorder point (units) calculated?
reorder point = average daily sales × lead time + safety stock.
Which figures do I need?
Average daily sales (units), supplier lead time, safety stock (units). Take them from the same period and the same set of accounts or reports so the ratio is consistent, and check the example values as a guide to the units expected.
Which fees should I include?
Every fee your platform or provider charges on a sale: commissions, payment processing, fulfilment, storage, advertising and the expected cost of returns. Fee schedules change, so check the current rate card.
