Commerce Tally

Inventory Turnover Calculator

Calculate your inventory turnover ratio and days inventory outstanding to understand how efficiently you manage inventory.

Commerce Tally provides free educational calculators for ecommerce sellers. All results are estimates only and should not be considered financial, tax, legal, accounting, shipping, or business advice.

Calculate Inventory Turnover
Enter cost of goods sold and average inventory
$

Annual COGS

$

(Beginning + Ending) / 2

Cash is tied up in what sits on shelves

Know your turnover? See how inventory shapes profit

Slow-moving inventory ties up cash and eats storage costs. Your turnover rate shows how fast product becomes profit — and where discounts or pricing changes could move it faster.

A high turnover number is usually good — but it can also mean you're often out of stock and leaving sales on the table.

Last updated: July 17, 2026 | Reviewed by the Commerce Tally Editorial Team

About This Inventory Turnover Calculator

Use the inventory turnover calculator to understand how quickly inventory is sold and replaced. Ecommerce sellers need enough stock to avoid missed sales, but too much stock ties up cash, creates storage fees, increases markdown pressure, and raises the risk of obsolete inventory.

How to Use the Calculator

  1. Enter cost of goods sold for the period.
  2. Enter average inventory value for the same period.
  3. Review inventory turnover ratio.
  4. Review days inventory outstanding if available.
  5. Compare the result by category or SKU instead of only storewide.

How the Math Works

Inventory turnover equals cost of goods sold divided by average inventory. Days inventory outstanding estimates how many days inventory sits before being sold, often calculated as days in period divided by turnover.

Calculator results are estimates, not official platform statements. Marketplace fees, processor rates, carrier charges, taxes, return costs, and discounts can change by category, region, seller account, customer location, and timing. Use the result as a planning checkpoint, then confirm important assumptions with your marketplace dashboard, accounting records, shipping software, or a qualified professional.

Interpretation Tips

  • High turnover can be healthy, but stockouts can hide demand.
  • Low turnover may indicate overbuying, weak demand, poor pricing, or seasonal inventory.
  • Track turnover by product line because averages can hide slow movers.
  • Use turnover with margin data so fast-selling low-profit items are not overvalued.

Inventory Turnover Calculator FAQ

What is a good inventory turnover ratio?

It depends on category, seasonality, lead time, and margin. Compare similar products and your own history.

Can turnover be too high?

Yes if it means frequent stockouts or emergency reorders.

Should inventory be measured at cost or retail?

Turnover is commonly calculated with cost-based inventory and cost of goods sold.