Convert US Oil Barrel to US Gallon
Convert us oil barrels to us gallons instantly. 1 us oil barrel = 42 us gallon — use the live calculator, the exact formula, a conversion table and worked examples. Also check the US Gallon to US Oil Barrel converter for the reverse conversion.
Units explained
US Oil Barrel
The petroleum barrel is exactly 42 US gallons (158.987 L).
Set by the US petroleum industry in the 1860s and now a global oil-trade standard.
The standard unit for crude-oil pricing and production worldwide.
US oil industry, 1860s.
US Gallon
The US liquid gallon is defined as exactly 231 cubic inches (3.785411784 liters).
Based on the English wine gallon of 231 cubic inches, retained by the US after 1824.
The primary US unit for fuel, milk and large beverage containers.
English wine gallon; US since 1824.
US Oil Barrel to US Gallon conversion formula
The relationship between us oil barrels and us gallons:
To convert us oil barrels to us gallons, multiply the value in us oil barrels by 42. To reverse, multiply us gallons by 0.0238095238.
How to use this converter
Type a value into the calculator. The result in us gallons updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the US Gallon to US Oil Barrel converter for the reverse direction.
Step-by-step: convert us oil barrels to us gallons
- Write down the value in us oil barrels (bbl (oil)).
- Multiply that value by the factor 42.
- The product is the equivalent value in us gallons (gal).
- To reverse, multiply the us gallon value by 0.0238095238.
Worked examples
Example 1 — Convert 1 bbl (oil) to gal:
1 × 42 = 42 gal
Example 2 — Convert 100 bbl (oil) to gal:
100 × 42 = 4200 gal
Real-world example — Fabric and tailoring
One us oil barrel of fabric converts to a value in us gallons commonly used for seam allowances. Garment patterns frequently switch between the two units on a single instruction sheet.
1 bbl (oil) × 42 = 42 gal
Real-world example — Body height conversion (reverse direction)
You measure 1.75 us oil barrels tall and need to fill in a gym membership form or medical record that asks for height in us gallons. This is the most-used everyday length conversion in metric-using countries.
1.75 bbl (oil) × 42 = 73.5 gal
Real-world example — Pet and accessory dimensions
A 3-us oil barrel dog leash equals a tidy round value in us gallons. Pet-supply shopping frequently mixes the two units across product specifications.
3 bbl (oil) × 42 = 126 gal
US Oil Barrel to US Gallon conversion table
Standard reference values for converting us oil barrels to us gallons:
| US Oil Barrel [bbl (oil)] | US Gallon [gal] |
|---|---|
| 0.01 | 0.42 |
| 0.1 | 4.2 |
| 1 | 42 |
| 2 | 84 |
| 3 | 126 |
| 4 | 168 |
| 5 | 210 |
| 10 | 420 |
| 20 | 840 |
| 30 | 1260 |
| 40 | 1680 |
| 50 | 2100 |
| 100 | 4200 |
| 500 | 21000 |
| 1000 | 42000 |
Frequently asked questions
How many us gallons is 1 us oil barrel?
How do I convert us oil barrels to us gallons?
How do I convert us gallons back to us oil barrels?
How many us gallons is 100 us oil barrels?
Popular volume unit conversions
Convert US Oil Barrel to other volume units
Show all US Oil Barrel conversions
Metric / SI (8 units)
US Customary (Liquid) (7 units)
Imperial (UK) (4 units)
Cubic (length-derived) (3 units)
Cooking / Culinary (3 units)
Sources & references
Conversion factor (1 bbl (oil) = 42 gal) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.