A half barrel is the keg most people picture when they say "a keg". It is
half of a US beer barrel, and the US beer barrel is defined as exactly 31 US
liquid gallons — so a half barrel is 15.5 US gallons.
Quick answer
1 half barrel = 15.5 US gallons = 58.67 litres = 1,984 US fl oz, which
pours 124 pints (16 oz) or 165 bottles (12 oz).
The numbers
| Measure | Value |
|---|---|
| US gallons | 15.5 |
| Litres | 58.67 |
| US fl oz | 1,984 |
| 16 oz pints | 124 |
| 12 oz servings | 165 |
| Imperial pints (20 oz) | 103 |
| Empty (tare) weight | 29.7 lb / 13.5 kg |
| Full weight | 160.5 lb / 72.8 kg |
| Height × diameter | 23.3 in × 16.1 in |
| Coupler | Sankey D (US domestics and most craft) |
How much beer is left?
Weigh the keg, subtract the 29.7 lb tare, and divide the remainder by 8.34 lb
per gallon. A half barrel reading 90 lb on the scale holds about
(90 − 29.7) / 8.34 ≈ 7.2 gallons, a little under half.
Will it fit?
At 16.1 in across, a half barrel needs a full-size kegerator or a converted
chest freezer. Most single-tap home kegerators are built around a sixtel or a
corny keg — check the internal diameter before buying.
Half barrel vs 50 L Euro keg
They are often sold as equivalents but they are not: a 50 L keg is 13.2 US
gallons, about 15% less beer than a half barrel. Confirm with the
litres to gallons converter before comparing prices.
Key takeaways
- 15.5 gallons is a definition, not an approximation: half of a 31 gallon barrel.
- Expect 124 pints in theory and about 118 after foam loss.
- A full half barrel is a two-person lift at 160 lb.
- See the full keg size chart for every other size.