Inventory Turnover Calculator 2026: COGS, Sell-Through, and Sourcing Decision
Use COGS, average inventory, unit movement, stale stock, revenue, and storage cost to decide whether to keep sourcing, reprice, or clear inventory.
Inventory presets
Accounting period and cost basis
Unit movement and storage
Editable planning target
Category targets are editable planning thresholds, not official benchmarks. The turnover formula itself uses COGS divided by average inventory.
Reprice and restrict sourcing
Set markdown rules for stale units and source only proven fast sellers until sell-through improves.
Metric breakdown
| Metric | Value | What it means |
|---|---|---|
| COGS | $900.00 | Beginning inventory plus purchases minus ending inventory. |
| Average inventory cost | $2650.00 | Average dollar value tied up during the period. |
| Period turnover | 0.3x | How many times the average stock turned in this period. |
| Gross margin | 60.9% | $1400.00 gross profit before operating expenses. |
| Stale stock share | 18.5% | 25 stale units out of 135 ending units. |
| Storage drag | 26.1% | $730.00 annualized storage vs ending cost. |
Source more
Only increase buying in categories that match this velocity.
Reprice stale units
Create a markdown, relist, or bundle list for slow stock.
Freeze a category
Stop new buys until COGS and unit movement show cash recovery.
Formula and source notes
Checked 2026-08-08. The core formula is inventory turnover = COGS divided by average inventory. Amazon's seller tools also frame inventory health as an efficiency and sell-through problem, but this standalone calculator does not claim Amazon category benchmarks.
What reseller job this solves
This calculator helps decide whether cash is moving through inventory fast enough to keep sourcing, or whether the next action should be repricing, bundling, relisting, or pausing buys.
It uses inputs resellers can pull from bookkeeping and inventory counts: beginning cost, purchases, ending cost, units sold, ending units, stale units, revenue, and storage cost.
Risks this prevents
- Revenue illusion: sales can look healthy while ending inventory cost keeps climbing.
- Death-pile blindness: stale unit share catches cash trapped in old listings even if turnover looks acceptable.
- Bad sourcing timing: a low score tells you to recover cash before adding more inventory.
- Storage drag: annualized storage cost shows when rent or bins are quietly taxing the category.
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