Density & Buoyancy Calculator
Choose supplied-value density and buoyancy, or a separate material estimate using typical density. Estimate mass in kg from m³, or volume in m³ and litres from kg.
Enter positive values to calculate density and buoyancy.
Calculation result
A QUICK WALKTHROUGH
How to use this tool
- Enter mass and object volume in kg and m³.
- Enter displaced volume and fluid density in m³ and kg/m³.
- Review density and buoyant force, or switch to material estimates and optionally compare 11 materials.
Explicit SI formulas
Density is mass divided by object volume. Buoyant force is fluid density × 9.81 m/s² × displaced volume.
User supplied assumptions
The supplied-value mode uses your fluid density and displaced volume. The separate material mode estimates mass = density × volume or volume = mass / density using 11 typical approximate densities.
Calculation aid only
Typical material densities vary with composition, temperature and conditions, especially wood, concrete, air and water. Material outputs are estimated mass in kg or volume, not force, structural load or shipping safety advice. Buoyancy results do not guarantee floating behavior or engineering suitability.
GOOD TO KNOW
Common questions
Which units are required?
Enter mass in kilograms, volumes in cubic metres, and fluid density in kilograms per cubic metre.
Does it decide whether something floats?
It shows density and a simple force comparison; it does not provide an engineering guarantee.
Where does 9.81 come from?
Only the supplied-value buoyancy mode uses 9.81 m/s² as standard gravity; material mass estimates do not use gravity.
Can I estimate material volume or compare masses?
Choose one of 11 typical densities. Enter positive volume up to 1,000,000,000 m³ to estimate kg and optionally compare all materials, or mass from zero to 1,000,000,000 kg to estimate m³ and litres. Densities are approximate.