Inventory & Cashflow

Inventory Turnover Calculator

How many times your inventory sells out and replenishes in a period. Higher is better — until you stock out.

Inputs

Total cost of goods sold for the year $ Please enter a valid number.
(Beginning inventory + ending inventory) ÷ 2 $ Please enter a valid number.

Results

Inventory turnover ratio
Days of inventory on hand
Weeks of supply

All calculations run in your browser. Nothing is sent to a server. Last updated: 2026-07-19 · Formula verified against published sources (see below).

Formula
Inventory turnover = COGS ÷ Average inventory value

What inventory turnover means

Inventory turnover measures how many times you sell through and replenish your inventory in a period. A turnover of 6× means you sell your entire inventory 6 times per year (roughly every 2 months). Higher is generally better — capital isn't tied up in stock — until you start stocking out.

The formula

Inventory turnover = COGS ÷ average inventory

Days of inventory = 365 ÷ turnover

What's a "good" turnover?

It depends heavily on category:

For dropshippers who don't hold stock (the supplier holds it), turnover is less relevant — but if you private-label or hold bestsellers, it's a key metric. Turnover below 2× means you're tying up capital for over 6 months at a time.

Worked example

InputValue
Annual COGS$50,000
Average inventory$5,000
Turnover10.00× per year
Days of inventory37 days
Weeks of supply5.3 weeks

10× turnover is healthy. You hold about 5 weeks of supply at any time. If turnover drops to 4× (91 days of supply), you may be overstocked. If it rises to 20× (18 days), you may be at risk of stocking out.

Frequently asked questions

Does inventory turnover apply to dropshipping?
Only if you hold some inventory — samples, private-label stock, or bestsellers you ship yourself. Pure dropshippers (supplier ships directly) don't carry inventory, so turnover isn't relevant. But many dropshippers hold bestsellers privately for faster shipping, and turnover matters for those.
Not financial advice. This calculator is a math tool, not financial advice. Profit margins, ad spend, and business decisions depend on your specific situation. Consult a licensed accountant or financial advisor before making material business decisions.

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