What is US gallon?

A US gallon is a volume unit equal to 128 US fluid ounces, or approximately 3.785 litres. It is the standard unit for fuel, milk, and other liquid products in the United States.

Real-world uses

US gallons are used for fuel pricing and vehicle fuel economy (miles per gallon) in the United States. Milk, water, and paint are commonly sold in gallon containers. Pool volumes and water heater capacities are specified in gallons.

History

The US gallon is based on the English wine gallon of 231 cubic inches, which was defined by Queen Anne in 1707. When Britain adopted the Imperial gallon in 1824 (based on water weight), the US retained the older wine gallon standard.

Common mistakes

Confusing US gallons with Imperial gallons: a US gallon is about 3.785 litres while an Imperial gallon is about 4.546 litres—roughly 20% larger. This causes major confusion when comparing fuel economy between US and UK figures.

What is teaspoon (metric)?

A metric teaspoon is a volume unit equal to exactly 5 millilitres. It is a standard unit in cooking recipes and pharmaceutical dosing instructions across metric countries.

Real-world uses

The metric teaspoon (5 mL) is used in cooking recipes, pharmaceutical dosing instructions, and nutrition labelling. It is the standard dosing spoon for children's liquid medicines. Most international recipes specify teaspoon measurements assuming the 5 mL metric standard.

History

The teaspoon originated as a unit of apothecary measure in the 18th century, roughly the volume of a small spoon used to stir tea. The metric teaspoon was standardized at exactly 5 mL to align with the metric system and simplify pharmaceutical dosing.

Common mistakes

Confusing the metric teaspoon (5 mL) with the US customary teaspoon (4.929 mL) or the older Imperial teaspoon (3.55 mL). Also, using a household spoon instead of a measuring spoon—actual spoons vary widely in size.

When is this conversion used?

Fuel economy, beverage volumes, and liquid measurements frequently require converting between litres and US gallons, especially for automotive and cooking contexts across different markets.

Worked examples

1 US gallon = 757.0823568 teaspoon (metric)

1 teaspoon (metric) = 0.005 litre

How to convert US gallon to teaspoon (metric)

To convert US gallon to teaspoon (metric), multiply the value by 757.0823568.

To convert teaspoon (metric) back to US gallon, multiply by 0.00132086.

Measurement standards

The cubic metre is the SI derived unit of volume. The litre, equal to exactly one cubic decimetre (0.001 m³), is accepted by the BIPM for use alongside SI units. Both the lowercase "l" and uppercase "L" are approved symbols for the litre.

Did you know?

An Olympic swimming pool holds 2,500 cubic metres of water — about 2.5 million litres. The Amazon River discharges roughly 209,000 cubic metres per second, enough to fill 84 Olympic pools every single second.

Quick reference: US gallon to teaspoon (metric)

US gallonteaspoon (metric)
0.175.70823568
0.5378.5411784
1757.0823568
21,514.1647136
53,785.411784
107,570.823568
2518,927.05892
5037,854.11784
10075,708.23568
250189,270.5892
500378,541.1784
1,000757,082.3568

Common values

US gallonteaspoon (metric)
A teaspoon0.00132086 US gallon1 teaspoon (metric)
A cup of coffee0.06604301 US gallon50 teaspoon (metric)
A water bottle0.13208603 US gallon100 teaspoon (metric)
A bathtub79.25161571 US gallon60,000 teaspoon (metric)
A swimming pool (Olympic)660,430.13089537 US gallon500,000,000 teaspoon (metric)