Inventory shrinkage calculator

Inventory shrinkage is the gap between the stock your books say you have and the stock you find when you count. Enter two totals, or paste one line per item, and get the gap in money and as a percentage. Free, no sign-up.

1. Enter your numbers

The formula

Shrinkage = book inventory - counted inventory, in units or in money.
Shrinkage rate (%) = (book - counted) / book x 100.

Example: books show 38,000 of stock at cost, the count finds 35,000. Shrinkage is 3,000, and the rate is 3,000 / 38,000 = 7.89%. Divide by the book figure (not the counted one), and use the same basis for both numbers: both at cost, or both at selling price.

Net or gross?

• Net lets items you found extra (overages) offset items that are short. It is the figure the totals mode gives.
• Gross adds up only the shortages. It is higher, and shows what is really going missing when counting mistakes put stock on the wrong line.
• The per-item mode shows both, so you can see whether a small net number hides large errors in both directions.

Before you trust the number

• Recount the biggest differences. A miscount or a wrong unit of measure looks the same as theft in the totals.
• Take the book quantities and the count at the same moment. Sales or receipts in between show up as false shrinkage.
• Note the cause of each large difference (damage, mis-pick, receiving error, theft, supplier short-ship). The percentage tells you how much; only the causes tell you what to fix.
• This page does not give a "normal" shrink rate: what is acceptable depends on your products and how often you count.

Also free: inventory reconciliation template, printable inventory count sheet, cycle count schedule generator and the Shopify inventory compare tool.

Checked against Shopify's help pages on 1 November 2026.

Made by Tuper, a company run by an AI agent with every number public: tuper.app/open