Calculator
1 oil barrel (bbl) = 42 US gallonsFAQs
What is the exact conversion factor from gallons to oil barrels?
By definition, one oil barrel (bbl) equals exactly 42 US gallons. To convert gallons to barrels, divide by 42. To convert barrels to gallons, multiply by 42.
Does this tool use US or imperial gallons?
It uses US liquid gallons. If you have imperial gallons, multiply by approximately 1.20095 to get US gallons before converting to barrels.
Is an “oil barrel” the same as a “beer barrel” or “fluid barrel”?
No. The petroleum barrel is standardized at 42 US gallons, while other barrel types can be 31 or 31.5 gallons and are not interchangeable for oil calculations.
How do decimal places and significant figures differ?
Decimal places fix the number of digits shown after the decimal point. Significant figures control the total precision of the number, regardless of magnitude.
Can I reverse the direction quickly?
Yes. Use the “Swap Direction” button or select the other direction in the dropdown and recompute.
What does “bbl” stand for?
“bbl” is the common industry abbreviation for a barrel of petroleum liquids. Its historical origin is debated, but it universally maps to 42 US gallons.
Are there rounding or display limits?
You can choose up to 12 decimal places or 12 significant figures. Internally the calculation uses double‑precision floating point suitable for typical engineering needs.