Guide
Case and bottle math for wine distributors
A case is not a unit. It is a 12-pack of 750s until it is a 6-pack of magnums, a 24-pack of splits, or a keg. Here is how bottles, pack sizes, 9-liter equivalents, liters, and gallons fit together, and where the arithmetic goes wrong.
Why a case is not a unit
Every part of the wine trade counts in a different unit. Reps sell cases. The warehouse picks bottles. Suppliers and market data speak in 9-liter case equivalents. The state taxes liters or gallons. Price lists carry a bottle price and a case price, and one is supposed to be derived from the other.
That would be fine if a case were always twelve 750ml bottles. It is not. The same producer might ship a 12-pack, a 6-pack, a 6-pack of magnums, and a 3-pack of double magnums, all called “a case” on the invoice. Any system, spreadsheet, or habit that assumes 12 will be right most of the time and silently wrong on the SKUs where it matters.
The four units and how they relate
- Bottles are the atom. A bottle of a given SKU is always the same thing, which is why inventory should be kept in bottles.
- Cases are a property of the SKU: the pack size the producer ships. Cases equal bottles divided by that SKU's pack size, and nothing else.
- 9-liter case equivalents are the industry's comparison unit: total liters divided by nine. A 6-pack of 750s is half a case equivalent; a 6-pack of magnums is a full one.
- Liters and gallons are what tax returns and some depletion formats want. Both come from bottle size times bottle count. One liter is 0.264172 US gallons.
The rule that keeps all four consistent: store bottle size and pack size on every SKU, keep counts in bottles, and derive everything else. Never convert volume from a case count, because the case count does not know how big the bottles are.
Conversion table for common formats
| Format | Bottles per case | Liters per case | 9L case equivalents | US gallons |
|---|---|---|---|---|
| 12 × 750ml | 12 | 9.000 | 1.000 | 2.378 |
| 6 × 750ml | 6 | 4.500 | 0.500 | 1.189 |
| 12 × 375ml (halves) | 12 | 4.500 | 0.500 | 1.189 |
| 24 × 187ml (splits) | 24 | 4.488 | 0.499 | 1.186 |
| 12 × 500ml | 12 | 6.000 | 0.667 | 1.585 |
| 6 × 1L | 6 | 6.000 | 0.667 | 1.585 |
| 6 × 1.5L (magnums) | 6 | 9.000 | 1.000 | 2.378 |
| 3 × 3L (double magnums) | 3 | 9.000 | 1.000 | 2.378 |
| 1 × 20L keg | 1 | 20.000 | 2.222 | 5.283 |
Liters per case is bottle size times pack size. Case equivalents are liters divided by nine. Gallons are liters times 0.264172. Splits are the one common format that does not land on a round number.
Three worked examples
- A rep writes 18 bottles of a 6-pack SKU. That is 3 cases of that SKU, 13.5 liters, and 1.5 nine-liter case equivalents. A system that assumes 12 per case shows 1.5 cases on the pick sheet and the warehouse pulls 9 bottles short.
- A supplier asks for monthly depletions on a magnum. You sold 30 bottles of the 1.5L, which is 5 six-packs. Report it as 30 bottles and 5.0 case equivalents (45 liters ÷ 9), not 5 cases, or the supplier will read it as half the volume it was. See the depletion report guide for the rest of that report.
- A gallon-based state return. You delivered 10 cases of 24 × 187ml sparkling. That is 240 bottles, 44.88 liters, 11.856 gallons. Multiplying 10 cases by 9 liters would report 90 liters, double the truth, and at a sparkling rate. The state-by-state compliance guide covers which states want liters and which want gallons.
Where the arithmetic goes wrong
- A global 12. A spreadsheet column that divides by 12 is right for most SKUs and wrong for every 6-pack, 3-pack, and keg. The errors are small enough per line to survive for months.
- Case price ÷ 12 for the bottle price. On a 6-pack that halves the bottle price. Derive bottle price from case price using the SKU's own pack size, and state the rounding rule once.
- Receiving in cases when the supplier shipped a different pack. A purchase order for 10 cases against a producer who switched to 6-packs receives 60 bottles into a system expecting 120.
- Inventory kept in cases. The first split case breaks the count. Keep bottles; show cases.
- Depletions in cases instead of case equivalents. A 6-pack SKU reported as cases looks like half its real velocity to the supplier, and a magnum looks like double.
- Bottle size stored as a word. “Magnum” cannot be multiplied. Store 1.5L and let the label say magnum.
- Case minimums that assume 12. A one-case minimum on a 3-pack of double magnums is 3 bottles, not 12. The rule has to read the SKU's pack size.
- Samples pulled in bottles, tracked in cases. One bottle out of a 6-pack is a sixth of a case, and rounding it away is how sample inventory drifts.
How PYLR keeps it straight
PYLR stores inventory in bottles and carries bottle size and pack size on every SKU. Case quantities on orders, pick sheets, and invoices are derived from bottles using that SKU's pack, so an order for 18 bottles of a 6-pack reads as 3 cases everywhere, and a case minimum on a 3-pack means 3 bottles. Wines a supplier sells only by the case can be marked case-only so a rep cannot write a split. Bottle size is parsed to liters for depletion and tax math, and a SKU whose size cannot be parsed is flagged rather than silently treated as 750ml. Kegs carry their own size with a pack of one and count as a single case for delivery fees.
See wine inventory management software for the inventory side, and wine sales rep software for how reps write orders in either unit.
Frequently asked questions
What is a 9-liter case?
The wine industry's standard unit of volume: twelve 750ml bottles, which is nine liters. It exists so that a 6-pack of magnums, a 12-pack of standard bottles, and a 24-pack of splits can be compared on one line. Suppliers, importers, and market data all report in 9L case equivalents.
Is a 6-pack half a case?
It is one case of that SKU and half a 9-liter case, if the bottles are 750ml. Both statements are true, which is why the two numbers have to be kept apart. To the warehouse and the invoice, a 6-pack is one case. To a depletion report or a supplier, it is 0.5 case equivalents.
How many gallons are in a case of wine?
A 9-liter case is 2.378 US gallons (one liter is 0.264172 gallons). A 6-pack of 750s is 1.189 gallons. Convert from the bottle size and count, not from the number of cases, because cases are different sizes.
How do kegs fit in?
A wine keg is one unit that holds many servings, so it needs its own size on the SKU (commonly 19.5 or 20 liters) and a pack size of one. For volume, a 20-liter keg is 2.22 nine-liter case equivalents. For freight and delivery fees most distributors count a keg as one case.
Should inventory be counted in bottles or cases?
Bottles. A bottle is the only unit that never changes meaning across SKUs. Cases are derived from bottles using the SKU's pack size, so a case count is always available and always consistent, and a split case never breaks the count.
What bottle sizes should a catalog support?
At minimum 187ml, 375ml, 500ml, 750ml, 1L, 1.5L, and 3L, plus keg sizes. Store the size as a number of liters or milliliters on every SKU, not as a word like Magnum, so tax and depletion math can read it.
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