Weeks of Supply Calculator
How many weeks current stock will last.
Weeks of supply
6.0 weeks
8.7 turns a year
How the Weeks of Supply Calculator works
Weeks of supply is the retail planner's default unit because it maps directly onto buying cycles. Everyone understands what six weeks of stock means; nobody has an instinct for what 8.7 turns means.
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 weeks of supply calculated?
Current inventory ÷ average weekly unit sales. 900 units selling 150 a week is 6 weeks of supply.
What is a healthy weeks of supply?
Typically 4-8 weeks for general retail — enough to cover lead time and the ordering cycle without trapping cash. Fast fashion runs much leaner; furniture and speciality goods run far longer.
How does it relate to turnover?
Inversely, and directly convertible: 52 ÷ weeks of supply gives annual turns. Six weeks of supply is roughly 8.7 turns a year. The two are the same information in different units.
Should I calculate it per product or overall?
Per product for buying decisions, overall for cash planning. An aggregate figure hides the pattern that matters most — a handful of overstocked lines beside several running short, averaging out to something that looks fine.