# Shrinkage Rate Calculator

> Calculate inventory shrinkage from book and physical stock values, as a percentage of sales (the usual retail measure) and of book inventory.

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

Shrinkage is stock you have recorded but cannot find: book inventory minus the physical count. Retailers usually report it as a percentage of sales for the same period.

Also called: Inventory shrink calculator, Stock loss calculator.

## Inputs
- Book (recorded) inventory (default 250000)
- Physical count (default 241000)
- Net sales for the period (default 600000)
- Currency

## Results
- Shrink as % of sales
- Shrinkage value
- Shrink as % of book inventory

## Formula

```
Shrinkage = Book inventory − Physical count;  Shrink rate = Shrinkage ÷ Net sales × 100
```

Where:
- Book inventory: what your records say you should have
- Physical count: what the stock count found
- Net sales: sales for the period since the last count

## Worked example
1. Shrinkage = 250,000 − 241,000 = 9,000.
2. Shrink rate = 9,000 ÷ 600,000 × 100 = 1.5% of sales (3.6% of book inventory).

**Result:** A $9,000 gap between book and counted stock on $600,000 of sales is a 1.5% shrink rate.

## What the result means

Shrink comes from theft, damage, supplier short-shipping and recording errors. Break it down by department or SKU to find where it happens; a sudden change often points to a process or system issue.

## Assumptions and limits
- Book and physical values use the same valuation basis.
- Sales cover the period since the previous count.
- A negative result (overage) usually means receiving or recording errors rather than a gain.

## Questions

### Why measure shrink against sales?

It is the standard retail convention, so figures are comparable between stores and with industry surveys.

## Related calculators
- [Retail Inventory Turnover Calculator](https://calculators.geekmidst.com/calculators/retail-inventory-turnover-calculator)
- [Percentage Calculator](https://calculators.geekmidst.com/calculators/percentage-calculator)
- [Ecommerce Return Rate Calculator](https://calculators.geekmidst.com/calculators/ecommerce-return-rate-calculator)

Source: GM¹X CalcVerse — https://calculators.geekmidst.com/calculators/shrinkage-rate-calculator