What is stock variance?

Your records say 40 bottles of gin. You count 36. Those four bottles are stock variance. In retail the same gap is called shrinkage: stock that left without being sold or recorded.

The formulas

Variance = counted stock − expected stock

Variance % = variance ÷ expected stock × 100

Value it at cost price. A negative variance means stock is missing; a positive one usually means something was received without being recorded.

A worked example

The gin is the line to look at first: the fewest units and the most money.

Where variance comes from

• Unrecorded waste — spoiled, dropped, sent back. See wastage.
• Over-pouring and over-portioning — the recipe says 25ml; the hand says otherwise.
• Delivery mistakes — short deliveries signed for in full.
• Counting and unit errors — a case counted as one bottle.
• Theft — by staff or customers. Less common than the others, but real.

Why it matters

Variance is profit you paid for and never sold. A few percent on a busy bar or shop is thousands a year — and the same items showing up count after count tell you exactly where to look.

Common mistakes

1. Only looking at the total. A small total can hide one big loss behind several small gains.
2. Correcting without investigating. The reason is the useful part.
3. Counting too rarely. Monthly variance has a month of possible causes.

Tracking it in DUMA

A stocktake in DUMA shows what was expected next to what you counted for each item, and updates the records from the count. Stock written off with a reason appears in the Waste & loss report, so the gap you cannot explain gets smaller.