Density Calculator
Density from mass and volume, or mass or volume from density, with the relative density and whether the object floats and how much of it sits below the surface.
Result
Density: 288 lb/ft³
For a solid, uniform object in still fluid. Hollow objects float by their average density, air included.
- Mass
- 5 lb
- Volume
- 30 in³ (0.0174 ft³)
- Relative density
- 4.6133
- In the fluid
- Sinks
https://calcgallery.com/chemistry/density-calculator/
Results come from the published equations applied to the values you enter. They are not electrical design, conductor sizing, laboratory safety or medical guidance. Weather indices describe a standard person in standard conditions and are not a forecast. Where codes apply, local rules vary and must be checked. Read the full disclaimer
How to use the Density Calculator
- Choose whether to solve for density, mass or volume.
- Enter the other two, in whatever units you have, from grams and litres to pounds and cubic inches.
- Read the answer, the relative density against water, and whether the object floats and how deep.
The formulas
density = mass ÷ volumemass = density × volumevolume = mass ÷ densityrelative density = density ÷ density of the fluidUnits are converted exactly before the calculation: 1 g/cm³ is 1,000 kg/m³, or about 62.43 lb/ft³.
Floating
Archimedes’ principle says a floating object displaces its own weight of fluid. For a uniform solid, that means the share of its volume below the surface equals its density divided by the fluid’s. The page shows that share whenever the object floats, and says it sinks otherwise. The reference fluid is water at 4 °C unless you change it.
Hollow objects
A steel ship floats because its average density, steel and the air inside together, is below that of water. For a hollow object, enter its total mass and its total outside volume.
With your numbers
- Density = mass ÷ volume = 2.268 kg ÷ 0.000492 m³ = 4,613.32 kg/m³
- Relative density = 4.6133
Quick reference
For a solid, uniform object in still fluid. Hollow objects float by their average density, air included.
| Example | Result |
|---|---|
| 2.7 kg in 1 L | Density: 2,700 kg/m³ |
| 0.6 kg in 1 L | Density: 600 kg/m³ |
| Mass of 2 L at 2,700 kg/m³ | Mass: 5.4 kg |
| Volume of 5.4 kg at 2,700 kg/m³ | Volume: 2 L |
| 5 lb in 30 in³ | Density: 288 lb/ft³ |
| Ice at 917 kg/m³, 1 L | Mass: 0.917 kg |
Where the numbers come from
The fixed figures this calculator relies on, and the published source each one was checked against. How the calculators are built and checked
1 source
NIST Chemistry WebBook, water at 4 °C and 0.101325 MPa: 999.9749 kg/m³ (IAPWS-95), https://webbook.nist.gov/cgi/fluid.cgi?ID=C7732185, rounded to the conventional 1000 kg/m³ of NIST SP 811 (2008) Appendix B, centimeter of water, conventional = 98.0665 Pa.
Used for
- The conventional density of water, 1000 kg/m³. Pure water at 4 °C, its densest, is 999.97 kg/m³.
Common questions about the Density Calculator
- What is relative density?
- The density of a material divided by the density of water, also called specific gravity. It has no units, so it is the same in any system. Aluminium, at about 2,700 kg/m³, has a relative density of 2.7.
- How do I know if something floats?
- A solid object floats when it is less dense than the fluid, that is, when its relative density is below 1. It then floats with exactly that fraction of its volume below the surface. Something at 600 kg/m³ floats in water with 60% submerged, which is Archimedes' principle in one division.
- Why does ice float with most of it hidden?
- Ice is about 917 kg/m³, so about 92% of it sits below the surface of fresh water. Seawater is denser, so slightly less of an iceberg is hidden. Change the fluid density in the advanced options to see it.
- Can I pick a material from a list?
- No. Material densities vary with composition, moisture and temperature, and each would need a cited source. Enter the density from your own data sheet, or work it out here from a mass and a volume you have measured.