Convert Gallons to Cubic Inches

Gallon (US)

Definition: A gallon is a unit of volume specifically regarding liquid capacity in both the US customary and imperial systems of measurement. The US gallon is defined as 231 cubic inches (3.785 liters). In contrast, the imperial gallon, which is used in the United Kingdom, Canada, and some Caribbean nations, is defined as 4.54609 liters. In both systems, the gallon is divided into four quarts. Quarts are then divided into two pints and pints are divided into two cups. A cup is comprised of two gills, making one gallon equal four quarts, eight pints, sixteen cups, or thirty-two gills. Further differentiating the US and the imperial gallon, a US gill is divided into four fluid ounces, while an imperial gallon is divided into five. A US fluid ounce is therefore 1/128 of a US gallon while an imperial fluid ounce is 1/160 of an imperial gallon.

History/origin: The term gallon most closely originates from "galon" in Old Northern French and developed as a system for measuring wine and beer in England, resulting in measures such as the wine gallon, ale gallon, and imperial gallon.

Current use: In the United States (US), gallons are often used for larger containers, such as half gallon tubs of ice cream or one-gallon cartons of milk. Gallons are also widely used in fuel economy expression in the US, as well as some of its territories. The imperial gallon is used even more sparingly than the US gallon, with most countries around the world using liters when referencing fuel.

Cubic Inch

Definition: The cubic inch (symbol: in³) is a unit of volume in the Imperial and United States customary systems of measurement. It is the volume of a cube with measurements 1 in × 1 in × 1 in. It is equal to 16.387064 cm³ or mL.

History/origin: The cubic inch is derived from the inch, a unit of length within the imperial and US customary systems of measurement. Since the 1950s and 1960s, with the adoption of the international yard, the inch has been defined as exactly 2.54 cm.

Current use: The cubic inch and cubic foot are still used in the United States, and to some extent in the United Kingdom. However, SI (International System of Units) units of measurement are also widely used throughout these countries.

In the US, the automotive and aircraft industries in particular use the cubic inch to some extent, though the SI derived or SI accepted units of volume (liter, milliliter, and cubic meter) are also used.

In the UK, automotive model numbers are sometimes denoted in cubic inches.