Convert gallons to barrels
A 55-gallon drum holds 1.3095 barrels of oil, because an oil barrel is exactly 42 US gallons. Type the number of gallons and the barrels appear as you type. The switches under the fields let you choose a US or imperial gallon and an oil, beer or liquids barrel.
How many barrels is a gallon?
One US gallon is 0.02381 of an oil barrel, or one forty-second of it. To convert, divide by 42: barrels = gallons ÷ 42. A thousand gallons make 23.8095 barrels, and 42 gallons make exactly one[1].
An imperial gallon is bigger, 4.546 litres against 3.785[1], so one imperial gallon is 0.02859 of an oil barrel. Beer works with a different barrel: in the US it holds 31 gallons, so you divide by 31 instead.
The first switch under the fields is Gallon type, with US and UK / Imperial. The second is Barrel type, with Oil, US beer, US liquids and UK beer. The symbol next to each field changes with your choice, so you always see which units the converter is using.
For the other direction, open the barrels to gallons converter. To see your gallons in litres first, try the gallons to litres converter.
Gallons and barrels: what each unit measures
The gallon is the everyday unit for liquids in the United States. It holds 231 cubic inches and divides into quarts, pints and fluid ounces[1], and the gallons to quarts converter shows the first step of that split.
The barrel bundles 42 gallons into one trading unit. Oil prices and output are quoted in it, and company reports write large amounts as Mbbl for a thousand barrels and MMbbl for a million[2].
Reports also use the barrel of oil equivalent, or boe. It measures energy rather than volume, so natural gas and oil can be added together in one production figure[2]. This converter works with volume only.
Gallons to oil barrels conversion table
| Gallons | From US gallons | From imperial gallons |
|---|---|---|
| 1 gal | 0.02381 bbl | 0.02859 bbl |
| 2 gal | 0.04762 bbl | 0.05719 bbl |
| 5 gal | 0.119 bbl | 0.143 bbl |
| 10 gal | 0.2381 bbl | 0.2859 bbl |
| 15 gal | 0.3571 bbl | 0.4289 bbl |
| 20 gal | 0.4762 bbl | 0.5719 bbl |
| 25 gal | 0.5952 bbl | 0.7149 bbl |
| 30 gal | 0.7143 bbl | 0.8578 bbl |
| 31 gal | 0.7381 bbl | 0.8864 bbl |
| 36 gal | 0.8571 bbl | 1.0294 bbl |
| 40 gal | 0.9524 bbl | 1.1438 bbl |
| 42 gal | 1 bbl | 1.2009 bbl |
| 50 gal | 1.1905 bbl | 1.4297 bbl |
| 55 gal | 1.3095 bbl | 1.5727 bbl |
| 75 gal | 1.7857 bbl | 2.1446 bbl |
| 84 gal | 2 bbl | 2.4019 bbl |
| 100 gal | 2.381 bbl | 2.8594 bbl |
| 150 gal | 3.5714 bbl | 4.2891 bbl |
| 200 gal | 4.7619 bbl | 5.7188 bbl |
| 250 gal | 5.9524 bbl | 7.1485 bbl |
| 300 gal | 7.1429 bbl | 8.5782 bbl |
| 500 gal | 11.9048 bbl | 14.297 bbl |
| 750 gal | 17.8571 bbl | 21.4455 bbl |
| 1,000 gal | 23.8095 bbl | 28.594 bbl |
| 2,000 gal | 47.619 bbl | 57.1881 bbl |
| 2,500 gal | 59.5238 bbl | 71.4851 bbl |
| 5,000 gal | 119.0476 bbl | 142.9702 bbl |
| 10,000 gal | 238.0952 bbl | 285.9405 bbl |
| 50,000 gal | 1,190.4762 bbl | 1,429.7023 bbl |
| 100,000 gal | 2,380.9524 bbl | 2,859.4046 bbl |
| 1,000,000 gal | 23,809.5238 bbl | 28,594.0458 bbl |
What fraction of a barrel is a keg?
| Keg | US gallons | US beer barrels |
|---|---|---|
| Full barrel | 31 US gal | 1 US bbl |
| Half barrel | 15.5 US gal | 0.5 US bbl |
| European 50-litre keg | 13.209 US gal | 0.42608 US bbl |
| European 30-litre keg | 7.925 US gal | 0.25565 US bbl |
| Quarter barrel | 7.75 US gal | 0.25 US bbl |
| Sixth barrel | 5.167 US gal | 0.1667 US bbl |
| 5-gallon keg | 5 US gal | 0.1613 US bbl |
How many barrels are in a 55-gallon drum?
A 55-gallon drum holds 1.3095 oil barrels. It is the steel drum sold as 200 litres outside the United States, and in Britain and its former dependencies an older size of 44 imperial gallons was common, now also filled to 200 litres[2]. That 44-gallon drum comes to 1.2581 barrels.
Counting stock in barrels is easy from there. A yard with 40 drums of 55 gallons holds 2,200 gallons, which is 52.38 oil barrels.
How do you convert gallons per minute to barrels per day?
US pumps are usually rated in gallons per minute, while wells and pipelines report barrels per day. Multiply gallons per minute by the 1,440 minutes in a day and divide by 42. In short: barrels per day = gallons per minute × 34.29.
A pump moving 100 gallons a minute around the clock shifts 144,000 gallons, or 3,428.57 barrels a day. You can type that daily total straight into the converter, or write it as 144 thousand.
Which number formats does this converter handle?
| What you type | What the converter shows | How we read it |
|---|---|---|
| 2.5 | 0.05952 bbl | The decimal point is read the way English writes it. |
| 2,5 | 0.05952 bbl | A comma pasted from a European document is read as a decimal point, so the result is the same. |
| 1,500 | 35.7143 bbl | Three digits follow the comma, so we read it as a thousands separator: the field holds fifteen hundred gallons. A note under the field shows the other possible reading, 1.5. |
| 3/4 | 0.01786 bbl | We work out the fraction ourselves, so there is no need to turn it into a decimal first. |
| ½ | 0.0119 bbl | The ½ character on its own counts as half a gallon. |
| 55 gal | 1.3095 bbl | A unit symbol pasted with the number is no trouble: we take the number and leave the symbol out. |
| 144 thousand | 3428.5714 bbl | The word thousand multiplies the number by a thousand, so we count 144,000 gallons. |
| 1.5 million | 35714.2857 bbl | The word million multiplies the number by a million, just as a reader of a report would. |
Convert other units to Barrels
Convert Gallons to other units
Sources
- Handbook 44 – 2026, Appendix C. General Tables of Units of Measurement — National Institute of Standards and Technology
- Barrel (unit) — Wikipedia
- 27 CFR 25.156, Determination of tax on keg beer — Electronic Code of Federal Regulations
Every figure in the tables was computed from the unit definitions and checked arithmetically before publication. Historical values and the names of local units come from the sources listed above.
Content last reviewed: · written and checked by the Arteon team
Frequently asked questions about gallons and barrels
Why does another calculator give more barrels for the same gallons?
Because it uses a different barrel. US tables of measures give a barrel for liquids as anything from 31 to 42 gallons, and many state laws fix it at 31.5[1]. A thousand gallons divided by 31.5 is 31.75 barrels, while divided by 42 it is 23.81 oil barrels. For crude and fuels the second figure is the right one, and the converter gives the first when you pick US liquids.
How many barrels of oil are in a cubic metre?
A cubic metre, or 1,000 litres, is 6.2898 oil barrels. Canadian oil companies measure crude in cubic metres and convert it to barrels when they export to the United States[2].
Is a barrel of water the same size as a barrel of oil?
Yes. A barrel measures volume, so 42 gallons of water make one barrel just as 42 gallons of crude do. In US oil fields, water pumped back into wells is reported the same way, in barrels of water per day[2].
Any questions or suggestions?
Write to us if the converter is missing a barrel or unit you need, or if any figure here looks out of date.