Density (ρ): The mass packed into each unit of volume. Water at room temperature is about 1,000 kg/m³ (62.4 lb/ft³) — materials denser than water sink in it, less dense ones float.
Mass: The total amount of matter. If you know an object's volume and its material, multiplying by density gives you its weight for shipping, structural, or recipe calculations.
Volume: The space the object occupies. Dividing mass by density tells you how much room a known weight of material will take up — useful for tank sizing, packaging, and storage.
Reference table: The material densities listed below the calculator are standard textbook values at roughly 20 °C (68 °F). Real-world density can shift with temperature, purity, and alloy composition.
How This Calculator Works
You enter any two of density, mass, and volume, and the tool solves for the missing third using ρ = m ÷ V (or its rearrangements m = ρ × V and V = m ÷ ρ). You can switch between metric (kg, m³) and imperial (lb, ft³) units. The reference table shows typical densities for common materials so you can fill in one value quickly.
Quick Questions
What is the difference between density and specific gravity?
Density is an absolute measurement (mass per volume in units like kg/m³). Specific gravity is density divided by the density of water, so it is a dimensionless ratio. A specific gravity of 2.7 means the material is 2.7 times as dense as water.
Does temperature affect density?
Yes. Most materials expand when heated, so their density drops as temperature rises. Water is unusual — it reaches maximum density near 4 °C (39 °F), which is why ice floats.
Can I use this for liquids and gases?
The formula works for any state of matter. For gases, density changes significantly with pressure and temperature, so use values measured at the same conditions you care about (often STP: 0 °C and 1 atm).
How do I find the density of an irregular object?
Use water displacement: submerge the object in a graduated container and measure the volume of water it displaces. Then weigh the object on a scale and divide mass by that displaced volume.