This converter allows you to convert between commonly used units of volume in the imperial system.
The converter offers a choice of three different units: a cubic foot, an imperial Gallon (used in the UK), and a Gallon (used in the US, hence referred to as the US Gallon throughout this article).
Simply choose your input unit from the menu below the ‘Convert From’ sign.
Then choose your output value from the menu below the ‘Convert To’ sign.
Alternatively, you may just swap the preselected options by clicking on the icon with the two arrows going in opposite directions. Once you are happy with your input and output selection, type in the value you want to convert as a decimal number, choose the number of decimal places you want your result to be rounded to, and click on ‘Convert’. You will receive the result rounded to the desired number of decimal places, in the output unit of your choice, alongside a rate, which determines the conversion, as we will show later on in the text.
The relationships between the three units determine the rates and formulas used for their conversions.
The following table will show all of the relationships from which we determine everything that follows.
Each row shows two values that are equivalent. The values are rounded to two decimal places. For more accurate calculations, use our converter.
| 1 cubic foot | 7.48 US Gallons |
| 1 cubic foot | 6.23 imperial Gallons |
| 1 imperial Gallon | 0.16 cubic feet |
| 1 imperial Gallon | 1.2 US Gallons |
| 1 US Gallon | 0.13 cubic feet |
| 1 US Gallon | 0.83 imperial Gallons |
Moving forward, we will now explain how each unit is converted to the other two, including formulae and examples.
The first unit we will have a closer look at is the cubic foot.
From the table we created, 4 important relationships need to be considered:
These rates lead to the following formulae:
The recommended way to use each formula is to select the one where the output is the subject of the formula (in our case, the left side of the equation). The four examples below will demonstrate how these formulae are used in practice for manual conversions.
EXAMPLE 1: Convert 2.5 $ft^3$ into US Gallons.
After choosing the first formula, we perform the following calculations.
EXAMPLE 2: Convert 33 US Gallons into $ft^3$.
The second formula will come in handy for this calculation.
EXAMPLE 3: Convert 17 $ft^3$ into Imperial Gallons.
We will apply the third formula.
EXAMPLE 4: Convert 2 Imperial Gallons into $ft^3$.
We substitute 2 Imperial Gallons into the fourth formula and calculate as follows.
The additional task we might want to tackle manually is converting between the two types of Gallons.
The rates between them are defined by the following two relationships:
This helps us derive two formulae:
The following examples will shed some light on their real-life application.
EXAMPLE 1: Convert 3 Imperial Gallons into US Gallons.
Using the first formula, the following calculations take place:
EXAMPLE 2: Convert 10 US Gallons into Imperial Gallons.
The second formula will come in handy, leading to the following calculations:
A cubic foot, as the name suggests, is the volume of a cube with a side length of exactly 1 foot.
The volume of such a cube in metric units is equivalent to 28.31 liters.
To gain some perspective on the cubic foot, here are a few items you might find around your house, and their volumes in cubic feet:
There are both Imperial Gallons and US Gallons due to historical reasons related to the units of measurement used in the British Empire and the United States.
The Imperial Gallon, also known as the British Gallon, was first introduced in England in the 16th century and was used as the standard unit of measurement for liquids in the British Empire, including the colonies that later became the United States.
However, after the American Revolution, the US decided to develop its own system of units, including the US Gallon. The US Gallon is defined as exactly 231 cubic inches, which is about 3.785 liters, and is used primarily in the United States for measuring liquids.
In 1824, the British adopted the Imperial measure in which the Gallon is based on 10 pounds or 277.42 cubic inches of water.
The historical background also refers to what the Gallon originally measured. The concept of the Gallon as a unit of measurement for liquids originated in England, specifically for wine and beer. The two systems used different sizes of Gallons, with the first based on the wine Gallon, which was equal in size to the US Gallon. The second system was based on either the ale Gallon or the larger Imperial Gallon.
Thus, both the Imperial Gallon and the US Gallon exist today due to the historical differences in measurement systems used in the British Empire and the United States.
Hi, my name is Andy Demar and I have been working in the postal industry for almost 15 years. I have seen and heard about it all - big packages, small parcels, suspicious boxes, difficulties with getting them from A to B.
