Convert Cubic Kilometer (km³) to Gallon (US) (gal (US)) instantly.
About these units
Cubic Kilometer (km³)
A cubic kilometer represents one billion cubic meters, making it a colossal volume unit used in geology, hydrology, glaciology, and planetary science. Large lakes, ice sheets, magma chambers, and atmospheric water content are often measured in km³. Earth's total ocean volume—about 1.335 billion km³—illustrates the unit's utility in describing planetary-scale systems. The km³ gives scientists a manageable number when dealing with natural features too massive for cubic meters or liters to express conveniently.
Gallon (US) (gal (US))
The US gallon is defined as exactly 231 cubic inches, or 3.785411784 liters. It is widely used in American commerce for gasoline, milk, water, and other household liquids. Its historical roots lie in old English wine and ale gallons, whose varying definitions ultimately led to divergent US and UK systems. Today, the US gallon remains deeply embedded in American culture, especially in automotive contexts—fuel economy ratings such as "miles per gallon" (MPG) illustrate its everyday relevance. Despite the global shift toward metric volume units, the US gallon persists due to familiarity and regulatory inertia. It remains an iconic unit, symbolizing uniquely American measurement traditions.