Retail Weeks of Supply

An inventory coverage KPI in weeks. Distinct from logistics inventory days of supply and from stock-to-sales ratio.

WOS = inventory ÷ average weekly sales.

Tip: Keep “Inventory” and “Average Weekly Sales” on the same basis (period, units, and population) before calculating Retail Weeks of Supply.

Cluster: Retail hub · ATV · Logistics fill rate · Logistics return rate · Percentage guide

Weeks of supply compares on-hand inventory to average weekly sales rate.

Enter inventory and average weekly sales for the same SKU or category (same unit basis).

On-hand inventory (units or $)
Average weekly sales (same UOM)

Weeks of Supply

Understanding Retail Weeks of Supply

How we calculate. WOS = inventory ÷ average weekly sales. The form uses the same arithmetic as the worked examples on this page. See our methodology and accuracy policy.

Real-world scenario: A typical Retail Weeks of Supply case uses inventory 1200 and average weekly sales 150. Enter the same figures below to reproduce the worked path.

What is Retail Weeks of Supply?

An inventory coverage KPI in weeks. Distinct from logistics inventory days of supply and from stock-to-sales ratio.

  • Same UOM for inventory and weekly sales (units or $)
  • Weekly sales = average run rate
  • Label retail vs cost dollars

The Formula

Retail Weeks of Supply
Weeks of supply = Inventory ÷ Average weekly sales

Worked Example

Scenario: Inventory 1,200 units; average weekly sales 150 units.
Step 1: 1200 ÷ 150 = 8
Answer: Weeks of supply is 8.0 weeks.

Common Use Cases

  • Replenishment: coverage checks
  • Markdown timing: excess weeks
  • Open-to-buy: WOS vs target

Pro Tips

  • Don’t use Logistics days-of-supply for store WOS
  • Freeze seasonal run-rate windows
  • Pair with sell-through

Limitations: Retail Weeks of Supply results are educational retail merchandising aids—not accounting, tax, or inventory-system advice. Confirm definitions with your POS, ERP, and brand reporting standards.

FAQ

Same as stock-to-sales?

Related coverage idea. Stock-to-sales is inventory÷period sales; weeks of supply uses a weekly sales rate denominator.

What if average weekly sales is 0?

Weeks of supply is undefined—enter positive average weekly sales.

Authoritative References

For retail merchandising and store performance concepts, consult: