ft³ to bbl Converter — Oil Barrels, Beer Barrels & US Liquid Barrels
Convert cubic feet to barrels instantly with our free ft3 to barrels calculator. Supports three core barrel types for US work plus a UK brewing standard: US oil barrels (42 gal), US beer barrels (31 gal), US liquid barrels (31.5 gal), and UK beer barrels (36 imperial gal). Whether you're working in petroleum engineering, craft brewing, or liquid chemical storage, this cubic feet to bbls converter gives you accurate results for the right barrel type. 1 cubic foot = 0.1781 oil barrels. Select your barrel type below and get instant results.
Oil Reference
1 ft³ = 0.1781 oil bbl
Beer Reference
1 ft³ = 0.2410 beer bbl
Reverse Factor
1 oil bbl = 5.6146 ft³
Select Barrel Type
Convert cubic feet to barrels for the currently selected barrel standard.
Barrels (bbl)
0.1781 bbl
US Oil Barrels (42 gal each)
1 ft³ × 0.178107 = 0.1781 bbl
Formula: bbl = ft³ × 0.178107
(1 US Oil Barrel = 42 US gallons = 5.61458 ft³)
US Gallons
7.48 gal
Liters
28.317 L
Cubic Meters
0.028 m³
Cubic Inches
1,728 in³
💡 Tip
In the oil industry, 'bbl' always refers to a 42-gallon US oil barrel. 1 bbl crude = 5.6146 ft³.
"Barrel" means different things in different industries. Always verify before converting.
bbl
Capacity
42 US gallons
158.987 liters
5.6146 ft³
9,702 in³
Uses
Conversion
1 ft³ = 0.17811 oil bbl
1 oil bbl = 5.6146 ft³
bbl or beer bbl
Capacity
31 US gallons
117.348 liters
4.1448 ft³
7,162 in³
Uses
Conversion
1 ft³ = 0.24137 beer bbl
1 beer bbl = 4.1448 ft³
bbl or liq bbl
Capacity
31.5 US gallons
119.240 liters
4.2109 ft³
7,276 in³
Uses
Conversion
1 ft³ = 0.23748 liq bbl
1 liq bbl = 4.2109 ft³
bbl (UK)
Capacity
36 imperial gallons
163.659 liters
5.7779 ft³
9,984 in³
Uses
Conversion
1 ft³ = 0.17307 UK beer bbl
1 UK beer bbl = 5.7779 ft³
The abbreviation "bbl" does NOT always mean the same thing. In petroleum contexts: bbl = 42 US gallons (oil barrel) In US brewing contexts: bbl = 31 US gallons (beer barrel) In UK brewing contexts: bbl = 36 imperial gallons Always confirm which barrel type is intended before converting. When in doubt, ask for the gallon or liter equivalent to verify.
Tip: use the bbl → ft³ tab above for the reverse calculation.
Oil & Gas: 1,000 ft³ natural gas ≠ oil bbl (gas uses Mcf, not bbl for volume) 1 bbl crude oil = 5.6146 ft³ Brewing: Half-barrel keg = 15.5 gal = 2.072 ft³ Quarter-barrel = 7.75 gal = 1.036 ft³ Sixth-barrel = 5.17 gal = 0.691 ft³
All four barrel types side by side for easy comparison.
| Cubic Feet (ft³) | US Oil Barrels (bbl) | US Gallons | Common Use |
|---|---|---|---|
| 1 ft³ | 0.1781 bbl | 7.481 gal | Reference unit |
| 5 ft³ | 0.8906 bbl | 37.40 gal | Small tank |
| 5.6146 ft³ | 1 bbl | 42 gal | 1 oil barrel ⭐ |
| 10 ft³ | 1.7811 bbl | 74.81 gal | Storage vessel |
| 25 ft³ | 4.4528 bbl | 187.0 gal | Small tank |
| 50 ft³ | 8.9054 bbl | 374.0 gal | Medium tank |
| 56.146 ft³ | 10 bbl | 420 gal | 10 barrels |
| 100 ft³ | 17.811 bbl | 748.1 gal | Large vessel |
| 280.73 ft³ | 50 bbl | 2,100 gal | Tank truck |
| 561.46 ft³ | 100 bbl | 4,200 gal | Small storage tank |
| 1,000 ft³ | 178.11 bbl | 7,481 gal | Large tank |
| 5,614.6 ft³ | 1,000 bbl | 42,000 gal | Tank farm unit |
US Oil Barrel (42 US gal): bbl = ft³ × 0.178107 ft³ = bbl × 5.61458 US Beer Barrel (31 US gal): bbl = ft³ × 0.241365 ft³ = bbl × 4.14479 US Liquid Barrel (31.5 US gal): bbl = ft³ × 0.237483 ft³ = bbl × 4.21094 UK Beer Barrel (36 imp gal): bbl = ft³ × 0.173072 ft³ = bbl × 5.77792
All barrel conversions go through gallons: Step 1: Know the barrel size in gallons US oil barrel = 42 US gallons US beer barrel = 31 US gallons US liquid barrel = 31.5 US gallons Step 2: Know ft³ per gallon 1 US gallon ≈ 0.133681 ft³ 1 ft³ ≈ 7.48052 US gallons Step 3: Multiply 1 US oil bbl = 42 × 0.133681 = 5.61458 ft³ 1 ft³ = 1 ÷ 5.61458 = 0.178107 bbl For UK barrels, use imperial gallons: 1 imperial gallon ≈ 0.160544 ft³ 1 UK beer bbl = 36 × 0.160544 = 5.77792 ft³
An oil storage tank measures 20 × 15 × 10 ft. What is its capacity in oil barrels?
Step 1: Calculate volume in ft³
20 × 15 × 10 = 3,000 ft³
Step 2: Formula: bbl = ft³ × 0.178107
Step 3: bbl = 3,000 × 0.178107
Step 4: bbl = 534.32
Result: 3,000 ft³ = 534.32 US oil barrels = 22,441 US gallons = 84,951 liters
A craft brewery wants a 15 bbl fermenter. What size in cubic feet do they need?
Step 1: Formula: ft³ = bbl × 4.14479 (beer bbl)
Step 2: ft³ = 15 × 4.14479
Step 3: ft³ = 62.17
Result: 15 beer bbl = 62.17 ft³
Approximate cylindrical tank sizing with height = 2× diameter gives about 41 inches diameter × 82 inches tall.
A chemical storage vessel is 8 ft in diameter and 12 ft tall. How many US liquid barrels does it hold?
Step 1: Cylinder volume formula V = π × r² × h
Step 2: V = 3.14159 × 4² × 12 = 603.19 ft³
Step 3: Formula: bbl = ft³ × 0.237483 (US liquid barrel)
Step 4: bbl = 603.19 × 0.237483
Step 5: bbl = 143.25
Result: 603.19 ft³ = 143.25 US liquid barrels
Six industry scenarios where ft³ to bbl conversion is essential.
Petroleum engineers and tank farm operators use cubic feet for structural design and barrels for production reporting, trading, and inventory audits.
Example: A 10,000 ft³ crude oil tank = 1,781 oil barrels = 74,805 US gallons = 283,168 liters. Natural gas still uses Mcf, not bbl, for primary volume reporting.
US breweries report production in beer barrels but frequently evaluate vessel geometry and floor plans in cubic feet.
Common brewery sizes: 1 bbl = 4.14 ft³ 7 bbl = 29.0 ft³ 15 bbl = 62.2 ft³ 30 bbl = 124.3 ft³ 60 bbl = 248.7 ft³
Chemical engineers often mix structural tank volumes in cubic feet with inventory and compliance reporting in barrels or gallons.
Example: 50 tanks × 200 ft³ = 10,000 ft³ total. In US liquid barrels: 10,000 × 0.237483 = 2,374.8 liquid barrels.
Civil and mechanical engineers size vessels in cubic feet, then convert to barrels for permit documents, client specs, and operating procedures.
Typical oil-tank ranges: 500–5,000 ft³ = 89–891 bbl 5,000–50,000 ft³ = 891–8,906 bbl 50,000+ ft³ = 8,906+ bbl
Analysts, traders, and compliance teams switch between ft³ and barrels when reconciling engineering documents against commercial reporting standards.
Always specify the barrel type in reports. The abbreviation "bbl" alone is ambiguous across oil, US brewing, and UK brewing contexts.
Cargo planners often see hold sizes in cubic feet or cubic meters, while petroleum manifests and liquid contracts are expressed in barrels.
Rough oil-cargo references: 500,000 ft³ = 89,054 bbl 5,000,000 ft³ = about 890,535 bbl 10,000,000 ft³ = about 1,781,070 bbl
Click any card to use this value in the calculator above.
These quick cards use US oil barrel reference values by default. Your current barrel type selection in the calculator stays unchanged.
Common questions about converting cubic feet to barrels.
It depends on the barrel type:
US Oil Barrel (42 US gal): 1 ft³ = 0.17811 bbl US Beer Barrel (31 US gal): 1 ft³ = 0.24137 bbl US Liquid Barrel (31.5 US gal): 1 ft³ = 0.23748 bbl UK Beer Barrel (36 imp gal): 1 ft³ = 0.17307 bbl
For petroleum contexts, use the 42-gallon US oil barrel. For US brewing, use the 31-gallon beer barrel.
Multiply cubic feet by 0.178107:
oil bbl = ft³ × 0.178107
Examples: • 10 ft³ × 0.178107 = 1.781 bbl • 100 ft³ × 0.178107 = 17.811 bbl • 1,000 ft³ × 0.178107 = 178.11 bbl
Reverse conversion: 1 oil bbl × 5.61458 = 5.6146 ft³
US Oil Barrel: 42 US gallons = 158.987 liters = 5.6146 ft³ Used for crude oil, refined petroleum products, and oil & gas reporting.
US Beer Barrel: 31 US gallons = 117.348 liters = 4.1448 ft³ Used for US brewing production and TTB reporting.
Key difference: 42 gallons vs 31 gallons 1 oil bbl = 1.3548 beer bbl 1 beer bbl = 0.7381 oil bbl
Always specify the barrel type. "bbl" by itself is ambiguous.
"bbl" most often means US oil barrels in international contexts:
bbl = ft³ × 0.178107
In US brewing, "bbl" means a 31-gallon beer barrel: bbl = ft³ × 0.241365
Examples with oil barrels: • 5 ft³ = 0.891 bbl • 50 ft³ = 8.905 bbl • 500 ft³ = 89.05 bbl
Use the barrel type selector in the calculator above to switch standards.
1 US oil barrel (42 US gallons) = 5.6146 ft³
To convert any number of oil barrels to cubic feet: ft³ = bbl × 5.6146
Examples: • 10 bbl = 56.15 ft³ • 100 bbl = 561.5 ft³ • 1,000 bbl = 5,615 ft³
For the reverse-direction calculator, use Barrels to Cubic Feet.
A half-barrel in US brewing is a standard full-size keg:
Half-barrel keg = 15.5 gal = 2.0724 ft³
Other common keg sizes: Sixth-barrel = 5.17 gal = 0.6908 ft³ Quarter-barrel = 7.75 gal = 1.0362 ft³ Half-barrel = 15.5 gal = 2.0724 ft³ Full barrel = 31 gal = 4.1448 ft³
This is half of a US beer barrel, not half of an oil barrel.
The 42-gallon oil barrel became the US petroleum standard in the 1860s during the Pennsylvania oil boom.
Early oil moved in wooden barrels. Forty-gallon barrels were common, but two extra gallons were often added to offset leakage during transport. That practice led to the 42-gallon standard.
In 1872, the Petroleum Producers' Association formally adopted 42 US gallons as the standard oil barrel.
42 US gallons = 158.987 liters = 5.6146 ft³
From cubic meters to cubic feet, compare volumes quickly with clear formulas and fast results.