# Retail Inventory Turnover Calculator

> Work out inventory turnover from cost of goods sold and average inventory, plus days of inventory on hand and an annualised turnover for shorter periods.

Category: Commerce & retail · Applies to: Worldwide · Last updated: 2026-10-29
Interactive calculator: https://calculators.geekmidst.com/calculators/retail-inventory-turnover-calculator

Inventory turnover is cost of goods sold divided by average inventory at cost: how many times you sold through your stock in the period.

Also called: Stock turn calculator, Inventory turns calculator.

## Inputs
- Cost of goods sold (default 600000)
- Opening inventory (at cost) (default 140000)
- Closing inventory (at cost) (default 100000)
- Days in period (unit days; default 365)
- Currency

## Results
- Inventory turnover
- Days of inventory
- Average inventory
- Annualised turnover

## Formula

```
Average inventory = (Opening + Closing) ÷ 2;  Turnover = COGS ÷ Average inventory;  Days of inventory = Days in period ÷ Turnover
```

Where:
- COGS: cost of goods sold in the period
- Opening, Closing: inventory valued at cost at the start and end

## Worked example
1. Average inventory = (140,000 + 100,000) ÷ 2 = 120,000.
2. Turnover = 600,000 ÷ 120,000 = 5 times.
3. Days of inventory = 365 ÷ 5 = 73 days.

**Result:** Selling $600,000 of goods at cost against $120,000 of average stock is 5 turns a year, or about 73 days of inventory.

## What the result means

Higher turnover means stock sells faster and ties up less cash, but too high can mean stock-outs. Compare with your own history and similar retailers, not a universal target.

## Assumptions and limits
- Both COGS and inventory are valued at cost.
- A simple average of opening and closing stock represents the period.
- Seasonal businesses should average monthly inventory counts instead of two points.

## Questions

### Why use COGS rather than sales?

Inventory is held at cost, so dividing sales (at retail) by inventory at cost overstates turnover. If you only have retail values, use sales and inventory both at retail.

### What is days of inventory?

Roughly how many days your current stock would last at the period’s rate of sale.

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Source: GM¹X CalcVerse — https://calculators.geekmidst.com/calculators/retail-inventory-turnover-calculator