The Density Calculator uses the formula density = mass ÷ volume. Choose what you want to find, enter the other two values with their units, and click Calculate.
The density calculator determines the density, mass, or volume of an object or substance using the fundamental relationship between these three properties. Density is one of the most important physical properties of matter, describing how much mass is packed into a given amount of space. Whether you are a student working through a physics or chemistry problem, an engineer specifying materials, a jeweler verifying a precious metal, or a hobbyist shipping a package, this calculator handles the math and the unit conversions for you. Simply choose whether you want to find density, volume, or mass, enter the two values you know along with their units, and the calculator returns the third.
Density is defined as mass per unit volume. In plain terms, it tells you how heavy a substance is for its size. A small lead ball feels much heavier than a same-sized rubber ball because lead is far denser - it contains much more mass in the same volume. Density is what determines whether an object floats or sinks in a fluid: objects less dense than water float, while denser objects sink. This is why a steel nail sinks but a massive steel ship floats - the ship's overall density, including all the air inside its hull, is lower than that of water.
Density is an intensive property, which means it does not depend on the amount of material present. A drop of pure water and a swimming pool full of pure water have exactly the same density. This makes density extremely useful for identifying substances and checking purity, since each pure material has a characteristic density at a given temperature and pressure.
The relationship between density, mass, and volume is captured in one simple equation:
ρ = m ÷ V
where ρ (the Greek letter rho) is density, m is mass, and V is volume. Because this is a single equation with three variables, knowing any two lets you solve for the third. Rearranging the formula gives:
To find mass: m = ρ × V
To find volume: V = m ÷ ρ
This calculator automates all three forms. For example, to find density you enter mass and volume; to find volume you enter mass and density; and to find mass you enter density and volume. The calculator converts your inputs to consistent units behind the scenes, so you can freely mix metric and imperial units.
The SI (International System of Units) unit for density is the kilogram per cubic meter (kg/m³). However, density is expressed in many different units depending on the field and the magnitude of the value. This calculator supports the most common ones:
Because the calculator works internally in SI units, you can enter mass in pounds and volume in liters and ask for density in g/cm³ without doing any manual conversion.
For instance, with the default values, a mass of 8,900 kg in a volume of 1 cubic meter gives a density of 8,900 kg/m³ - which happens to be the density of copper.
Here are approximate densities of familiar substances at room temperature, expressed in kg/m³ (divide by 1,000 to get g/cm³):
These values explain everyday observations: ice floats on water because it is slightly less dense, while a gold ring sinks instantly because gold is nearly twenty times denser than water.
While density is constant for a pure substance under fixed conditions, it can change with temperature and pressure:
Density calculations show up across many fields:
A closely related concept is specific gravity, which is the ratio of a substance's density to the density of a reference material - usually water for liquids and solids. Because it is a ratio, specific gravity has no units. For example, gold has a density of about 19,300 kg/m³ and water about 1,000 kg/m³, so gold's specific gravity is roughly 19.3. Specific gravity is convenient because it is the same number regardless of the unit system, making it popular in industries like gemology and brewing.
Density equals mass divided by volume (ρ = m / V). To find mass, multiply density by volume; to find volume, divide mass by density. This calculator handles all three arrangements automatically.
You can use any of the supported units and mix them freely - for example, mass in pounds and volume in liters. The calculator converts everything internally and gives the result in the unit you choose for the unknown value. The SI standard is kg/m³.
The gram was originally defined so that one cubic centimeter of water at 4°C has a mass of one gram, giving water a density of 1 g/cm³ (equivalent to 1,000 kg/m³). This makes water a convenient reference for density and specific gravity.
Yes. Most substances expand when heated, which increases their volume and lowers their density. Published density values are usually given at a specific reference temperature, commonly 20°C or 25°C.
Measure the object's mass with a scale, then measure its volume by water displacement - submerge it in a graduated container and record how much the water level rises. Enter both values into the Find Density mode to get the density.
No. All calculations run entirely in your browser, and nothing you enter is uploaded or saved to any server.
This Density Calculator is provided for educational and general informational purposes. It uses standard unit-conversion factors and the density formula; for critical scientific, engineering, or commercial work, verify results against authoritative references and account for temperature and pressure conditions.