At any given moment, there are about 20 million containers traversing our oceans. The products they're transporting are worth billions of dollars.

    Their journeys across those oceans wouldn't be possible if we didn't understand how density works. And that's just one real-world application of density.

    In this comprehensive guide, we'll define density and put you on the path to understanding density conversions. If you need help with the calculations, use our free density converter on over 40 metric and imperial density units.


    Why use a density unit converter?

    Unit conversions can definitely get tricky. There are so many conversion factors to remember that its tough to remember them all. And you should always check your work with a density conversion calculator, like the one on this page.

    If you have any feedback about the calculator, please let us know how we can make it better. Just drop us a line using our contact form.

    What is density?

    In order to understand what density is, perhaps you should know what it means to be "dense." When something is "dense," we think of it as closely compacted.

    So a densely populated city has tons of people living within its limits. And a densely populated forest has a lot of trees packed together.

    When we're talking about density in a scientific manner, this definition doesn't technically change. The only difference is its application. Instead of referring to city populations or the number of trees in a forest, we talk about the compactness of atoms.

    That compactness is described as the mass of an object divided by the volume of an object.

    Density = mass / volume


    Let's say that you own two golf balls which have the exact same weight. But one golf ball is smaller.

    Since density is defined as the mass of an object divided by that object's volume, the golf ball that is smaller is denser because its weight is distributed across less volume.

    What are common density units?

    Now that we have a handle on density, let's go over some common density units.

    As we said earlier, density is defined as the mass of an object divided by the volume of that object. Because we can measure both mass and volume in several different units, there are more than a few ways to express density.

    The most common density unit you'll see is kilograms per cubic meter (kg/m3). This unit is a metric unit and it's considered the SI unit of density. However, you might see density measured in kilograms per liter (kg/L) or grams per liter (g/L) in some places.

    If you live in the United States, you'll likely encounter density in pounds per cubic foot (lb/ft3). This unit is not a metric unit, so its use is limited outside of the U.S.

    When do you have to convert density?

    Whether you're measuring density in kilograms per cubic meter or pounds per cubic inch, density is density.

    Why, then, would you ever have to convert density?

    If you recall correctly, you'll see density measured in kg/m3 more often than you'll see it in other units of measure. Now imagine that you received much of your formal education in the United States.

    And in the United States, you measured density in pounds per cubic foot much of the time.

    So when you go elsewhere and need to work with density a conversion calculator can help you stay fluent.

    How are density conversions done?

    So how do you convert between the most common density units? Is there some formula that you can use to make conversions easy?

    Unfortunately, no. How you go about converting density depends on which units you're working with.

    Let's go over a couple of common conversions:

    Lb/Ft3 and Kg/m3

    When converting from lb/ft3 to kg/m3, you simply have to remember this conversion factor: 16.02. We express this as:

    1 lb/ft3 = 16.02 kg/m3

    That's roughly how many kg/m3 are in a single lb/ft3.

    To kg/m3

    So if a density is written as 3 lb/ft3, you multiply it by 16.02 to convert it to kg/m3.

    To lb/ft3

    And in order to go from kg/m3 to lb/ft3, you simply divide by 16.02.

    Kg/m3 to Kg/L

    When converting from kg/m3 to kg/L, the conversion factor you must remember is 0.001. We express this as:

    1 kg/m3 = 0.001 kg/L

    That is to say, 1 kg/m3 equals 0.001 kg/L.

    To kg/L

    So if a density is written as 7 kg/m3, you multiply it by 0.001 to convert it to kg/L.

    To kg/m3

    To go from kg/L to kg/m3, you must divide your density in kg/m3 by 0.001. This is the equivalent of multiplying by 1,000.

    What are the applications of density?

    There are several applications of density.

    As it turns out, the human body has a density that's slightly less than water's density. Or, at the very least, roughly the same as water's density.

    In any case, if an object has a lower density than a liquid, it will float in that liquid. And when you develop a more complex understanding of density, you can even find ways to make objects that wouldn't normally float stay above water.

    Such is the case in the example of the shipping vessels we mentioned earlier.

    Many shipping vessels are made of steel. But steel has a higher density than water. In other words, steel ships should sink when positioned atop water.

    Our knowledge of density, however, allows us to thwart nature. We get around this problem by not hammering all of the steel in a vessel flat. By building the ships in a certain manner, we force the ships to displace water.

    And by forcing them to do so, we effectively reduce these ships' density.

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