How Much Does A Foot Of Water Weigh

Close view of a chef measuring the weight of a glass of water in the kitchen

The weight of water can change based on factors like temperature or added salt.

Image Credit: alvarez/E+/GettyImages

Our lives revolve around h2o — for hydration, recreation and then much more than. And agreement how factors like temperature, state and density affect the weight of water can assistance you when it comes to cooking.

What Is the Weight of Water?

Scientists apply two measurement systems to define the weight of h2o. In the metric organization, which is more widely used effectually the world and in cooking, the unit weight of water is approximately 1 gram per cubic centimeter at 25 degrees Celsius, according to the National Library of Medicine. In imperial measurements, it's about 62.4 pounds per cubic foot at 77 degrees Fahrenheit.

Only the weight of water is best understood when you remember nigh it in terms of common quantities:

A cup of h2o weighs about 224 grams (half a pound), per the National Constitute of Standards and Technology.
A liter of water weighs about 1 kilogram (two.two pounds), according to the United States Geological Survey (USGS).
A gallon of h2o weighs about 3.79 kilograms (8.35 pounds), per the USGS.

Variations in the Weight of H2o

The weight of h2o is estimate, however, considering it can vary based on factors like temperature and pressure level, co-ordinate to the USGS. Information technology tin can also fluctuate if there are substances in the water, like salt.

Why It Matters

Water weight is important when it comes to cooking. Many recipes are based on the weight of ingredients, rather than stock-still amounts like tablespoons or cups. And then if you're lacking a food scale, understanding roughly how much certain quantities of h2o counterbalance tin can help yous ace any meal.

Water Density

The density of any substance will change as factors like temperature and pressure brand the material expand and contract, and water is no exception, co-ordinate to the USGS.

Density is a measure of how much mass a substance has, per the U.South. Nuclear Regulatory Commission (NRC). A small book of a very dumbo fabric like lead volition be heavy, whereas a large book of a low-density material like Styrofoam weighs much less.

Density is normally stated in units of mass per volume; for example, grams per cubic centimeter. On Earth, this means that the density of h2o at room temperature is the same as the weights listed above, per the USGS.

Weight vs. Mass

Most people don't brand a distinction between mass and weight, only to a scientist, these are two different measurements. Mass is the actual physical bulk of a substance, according to the NRC. Weight is the force with which gravity pulls on that mass.

For example, a true cat has more than mass than a mouse. Only a cat on the moon might weigh less than a mouse on Earth due to different gravitational pulls. Only considering you're likely simply dealing with h2o on World, the weight of water won't fluctuate based on gravity.

How H2o Density Varies

The weight and density of h2o can fluctuate based on its state, however. In improver to liquid, water can be a solid (ice) or gas (vapor), per the USGS. The density of ice, gas and liquid are dissimilar, which consequently changes water's weight from form to form.

Ever wonder why water ice floats? That'due south considering ice is less dense than water. When water freezes at 32 degrees F (0 degrees C), its molecules spread out to form a more rigid construction, co-ordinate to the USGS.

Vapor, on the other paw, occurs when liquid water hits 212 degrees F (100 degrees C) and the molecules move around rapidly and evaporate, according to the USGS. Consequently, gas is less dense than the other states of water.

Then there'southward common salt water to consider. Salt water is more dense — and thus weighs more than — than fresh water due to the added mass of table salt, according to the USGS.