Density Calculator
Calculate density using ρ = m/V
Density Calculator tool
Results
Density (kg/m³)
0.00
Density (g/cm³)
0.00
Density (g/mL)
0.00
Density (lb/ft³)
0.00
Density Calculator: key facts
- What it does
- Calculate density using ρ = m/V
- Category
- Science Calculators
- Cost
- Free, with no account, sign-up, or install.
- Your data
- Runs entirely in your browser — the files and text you enter are never uploaded to a server.
- Last reviewed
- . Report an incorrect result.
Understanding the Density Calculator
Density is mass per unit volume (ρ = m/V), a fundamental property of materials that determines whether objects float or sink and affects many physical and chemical processes. The Density Calculator solves for density, mass, or volume when you know the other two, supporting multiple unit systems for mass (kg, g, lb, oz) and volume (L, mL, m³, ft³, gal).
Students solve physics and chemistry homework problems, engineers select materials based on density requirements, and scientists analyze material properties. The calculator handles unit conversions automatically and displays results in multiple units for flexibility across different applications.
Because calculations run entirely in your browser using JavaScript, you can solve density problems without any data leaving your device. The tool explains common density applications in the FAQ section.
Getting a result
- Select what you want to calculate from the dropdown: density, mass, or volume.
- Supply the two properties you know — usually the sample's mass and its volume.
- Choose units that match your measurements, from grams and milliliters to pounds and gallons.
- Click Calculate to solve for the unknown variable using ρ = m/V.
- Check the computed value, reported in kg/m³, g/cm³, lb/ft³, and more.
Mass over volume, in any unit pair
Density is mass divided by volume, and the tool solves for any of the three. Its usefulness comes from being an intensive property — independent of how much material you have. A gram of gold and a tonne of gold have the same density, which is what makes the figure identify a substance in a way mass alone never could.
Inputs are converted internally to kilograms and cubic metres regardless of the units you select, so a mass in pounds and a volume in litres combine without difficulty. Watch the volume units in particular, since the relationships between millilitres, litres, cubic centimetres, and cubic metres trip people up more often than the arithmetic does.
Water is the reference worth carrying in your head: one gram per cubic centimetre, equivalently 1000 kg/m³. Anything denser than that sinks in water and anything less dense floats, which is the whole basis of buoyancy.
- The defaults — 1000 kg in 1 m³ — give 1000 kg/m³, the density of water.
- A 500 g object occupying 250 cm³ has a density of 2 g/cm³, so it sinks.
- Solving for mass: a 2 m³ block of aluminium at 2700 kg/m³ weighs 5,400 kg.
Reasons to use it here
- Density calculations execute client-side in your browser—no data is transmitted to any server, keeping your material property analysis private and functional offline.
- Solves for any of the three variables (density, mass, volume) when you know the other two, making it versatile for different problem types.
- Converts between metric and imperial measurement systems automatically, handling kg/g/lb/oz for mass and L/mL/m³/ft³/gal for volume.
- Displays density results in kg/m³, g/cm³, lb/ft³, and other common units simultaneously, matching the conventions of different scientific and engineering fields.
Temperature, pressure, and specific gravity
Density is not truly constant for a given substance, because volume changes with temperature and, for gases, dramatically with pressure. Most materials expand when heated and so become less dense. Water is the well-known exception below 4°C, where it expands as it cools further — which is why ice floats and why lakes freeze from the surface down rather than the bottom up. Any precise density figure comes with a stated temperature.
For gases the dependence is so strong that a density quoted without both temperature and pressure is meaningless; air at sea level is around 1.2 kg/m³ and considerably less at altitude.
Two related terms are worth distinguishing. Specific gravity is density relative to water, making it a dimensionless ratio — a specific gravity of 2.7 means 2700 kg/m³. And bulk density, used for powders, granules and aggregates, includes the air trapped between particles, so it is always lower than the density of the material itself. Using one where the other is meant is a common source of error in construction and materials work.
Frequently Asked Questions
What is the density formula?
The density formula is ρ = m/V, where ρ (rho) is density, m is mass, and V is volume. Density is typically expressed in kg/m³ in the SI system, but g/cm³ is common for solids and liquids. Water has a density of approximately 1 g/cm³ at 4°C.
Which mass and volume units does the tool handle?
The calculator supports kilograms, grams, pounds, and ounces for mass; and liters, milliliters, cubic meters, cubic feet, and gallons for volume. Density results are displayed in kg/m³, g/cm³, lb/ft³, and other common units.
Can I calculate mass or volume from density?
Yes — leave any one of the three properties as the unknown. If you know density and volume, you can calculate mass (m = ρV). If you know density and mass, you can calculate volume (V = m/ρ). The ρ = m/V relationship is inverted for you depending on the chosen target.
What is the density of water?
The density of water is approximately 1 g/cm³ or 1000 kg/m³ at 4°C. This value is used as a reference point—materials with density less than water float, while materials with density greater than water sink.
How does temperature affect density?
Most materials expand when heated and contract when cooled, which changes their density. For water, density is maximum at 4°C and decreases at both higher and lower temperatures. This is why ice floats on liquid water.
