How Many Quarts Are in a Gallon?

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There are exactly 4 US quarts in 1 US gallon. As it name implies, a “quart” makes up a quarter of a gallon. The quart itself holds 2 pints, 4 cups and 32 fluid ounces. The US customary system shares similar names to the British imperial system measurement units including the units for volume. While there are also 4 imperial quarts in 1 imperial gallon, the measurement of the volume units are not the same.

History of the US Customary Units of Measurement

The US customary unit of measurement is largely based on the English system, just like the British imperial system. Dating as far back as the Anglo-Saxon England in 450 CE, unit measurements such as the inch, foot and even acre were already in use.

Interestingly, the inch (or ynce) measured 3 barleycorns, which closely measures the modern day inch. Foot units during this time period came in 12 or 13 inches. Further influences on the English system came after the Norman invasion in 1066. The Normans, who had Norse, Frankish and Gallic-Roman ancestry, added the rod and furlong units.

The English system was the standard unit for measurement in the entire British Empire, which included the colonies in North America. After the American Revolution 1783, the English system remained as the standard system of measurement in the colonies. By 1821, then US Secretary of State John Quincy Adams determined through a study that measurements in all 22 states were uniform. This declaration in essence, standardized the US customary units of measurement.

Comparing US Customary Units and Imperial Systems of Measurement

The British imperial system of measurement was officially standardized in 1824, some three years after the US government deemed its customary units as being uniform. Measurements for most units in both systems such as length, area and distance remain identical.

When it comes to liquid volume units, however, US customary and imperial units have different measurements, even though both share the same names for the units. Here’s how the fluid capacity measurements differ between these two systems using the metric system.

US Customary Liquid Measures

1 US fluid ounce = 29.573 milliliters

1 US fl cup = 236.59 ml

1 US fl pint = 473.18 ml

1 US fl quart = 946.36 ml

1 US fl gallon = 3,784 ml


Imperial System Liquid Measures

1 imperial fl oz = 28.413 ml

1 imperial cup = 284.13 ml

1 imperial pint = 568.261 ml

1 imperial quart = 1,130 ml or 1.13 liters

1 imperial gallon = 4,546 mil or 4.546 liters

Metrication in the United States and the United Kingdom

Most countries around the world have adopted the metric system units as their standard for measuring length, distance, weight, area and fluid capacity. Discussions for metrication in the UK parliament started in the early 1800s and a formal government policy for its use was issued in 1965.

There were similar moves to adapt to the metric system of measurements in the United States since the 1800s and in the 1970s. While most in the UK are steadily adapting to the metric system, most in the US are slow to follow suit. However, the US has successfully adopted the metric system in the medical, scientific and technical fields.

Kitchen and Recipe Measurements

Distinguishing between US customary and imperial measurements when it comes to recipes can cause some confusion since both share the same volume unit names. Recipes using ounces or cups that are shared online seldom have any indications if they are in US customary or imperial systems.

One good way to guess whether the recipe portions are in US customary or imperial systems is to check for simple clues. Cups are seldom used in the imperial system, so if you see one in a recipe, the measurements are likely in US customary units. Americans, on the other hand, seldom use the gill measurement. Recipes that use this unit, therefore, are likely in imperial system units.

Converting Between Systems

The simplest workaround to nailing down recipes is to have a converter app on your smartphone and a dependable weighing scale in the kitchen with a conversion feature. Having measuring cups for US customary, imperial and metric units in your kitchen will also go a long way in helping you deal with the differences in recipe measurements.