How do you calculate inventory turnover?

Divide annual COGS by average inventory and apply any normalization factor. With $2,400,000 COGS and $300,000 average inventory at a factor of 1, turnover is 8 turns.

What does 8 inventory turns mean in days?

Days of supply is 365 divided by turnover, so 8 turns equals about 45.6 days of inventory on hand, roughly six weeks of stock.

What is the normalization factor for?

It rescales the ratio when your COGS and inventory cover different periods or units. At the default of 1 it leaves the raw ratio of 8 unchanged.

What is a good inventory turnover ratio?

Depends on the category, but 6-12 is typical for many manufacturers. The example's 8 turns is healthy, balancing capital efficiency against stockout risk.

Inventory turnover vs inventory turns, what's the difference?

They measure the same thing. Some tools derive average inventory from two snapshots; this one takes the average directly and adds a normalization factor and days-of-supply output.

How do I improve inventory turnover?

Reduce average inventory without losing service, tighten reorder points, cut safety stock where variability is low, and shorten supplier lead times so less buffer is needed.

Supply Chain & Procurement calculator

Inventory Turnover Calculator

Inventory turnover tells supply-chain and procurement teams how many times a year their average inventory is sold and replaced, a direct read on how hard working capital is being put to work. Unlike a two-snapshot calculation, this version takes your average inventory value directly and lets you apply a normalization factor to align periods or units. Procurement leaders use it to benchmark suppliers and categories, and to convert a turnover number into days of supply, the language warehouses actually speak. A higher turnover means less cash frozen in stock, but it must be balanced against the risk of running short.

What this calculator does

Calculate inventory turnover for Supply Chain & Procurement from annual COGS and average inventory value.
Use it to judge how hard inventory is working in Supply Chain & Procurement.
It computes inventory turnover as annual COGS divided by average inventory, scaled by a normalization factor, and converts the result to days of supply.

Formula used

Inventory turnover = annual COGS ÷ average inventory × normalization factor

Inputs explained

Annual cost of goods sold: Annual COGS (or usage value) flowing through inventory.
Average inventory value: Average inventory held over the year, at the same cost basis.
Normalization factor: Leave at 1; only change to rescale the ratio.

How to use the result

Use it when you already have an average inventory figure and want a quick turnover and days-of-supply read for a category, plant or supplier.
Turnover is only as good as your average-inventory figure; a single year-end snapshot used as the average can badly misstate velocity for seasonal stock.

Current U.S. benchmarks

U.S. manufacturing runs at 76.0% of capacity (Federal Reserve, Jul 2026). New factory orders are up 7.4% year over year (Census).
Importers paid an average effective tariff of 12.4% of customs value in 2025 across the 57 manufacturing import families MFG Calcs tracks (USITC DataWeb), up from 3.3% the year before. Statutory and effective rates by family, with top source countries, are at mfgcalcs.com/tariffs.
Sourcing currencies as of 2026-08-21 (Federal Reserve H.10): 6.721 CNY and 16.8909 MXN per USD. Landed-cost comparisons move with these daily rates.

Common questions

How do you calculate inventory turnover? Divide annual COGS by average inventory and apply any normalization factor. With $2,400,000 COGS and $300,000 average inventory at a factor of 1, turnover is 8 turns.
What does 8 inventory turns mean in days? Days of supply is 365 divided by turnover, so 8 turns equals about 45.6 days of inventory on hand, roughly six weeks of stock.
What is the normalization factor for? It rescales the ratio when your COGS and inventory cover different periods or units. At the default of 1 it leaves the raw ratio of 8 unchanged.
What is a good inventory turnover ratio? Depends on the category, but 6-12 is typical for many manufacturers. The example's 8 turns is healthy, balancing capital efficiency against stockout risk.
Inventory turnover vs inventory turns, what's the difference? They measure the same thing. Some tools derive average inventory from two snapshots; this one takes the average directly and adds a normalization factor and days-of-supply output.

Last reviewed 2026-08-12.