What density tells you about an object
Density describes how tightly mass is packed into a given volume. Two objects can be the same size and look identical, but if one is much heavier, it has a higher density — this is why a solid steel ball sinks in water while a same-sized foam ball floats. Density is one of the most basic ways to identify or compare materials, since every substance has a roughly consistent, well-documented density under normal conditions.
Common mistakes happen when mixing up units — grams with kilograms, or cubic centimeters with liters — which can throw a result off by a factor of 1,000. This calculator eliminates that problem by letting you choose your input and output units independently; all conversions happen internally.
How this calculator works
Enter mass and volume in whatever units you have on hand, pick your desired result unit, and the calculator normalises everything to a common base (grams and cm³) before dividing. The result is then converted to your selected density unit.
How to Calculate Density (step by step)
Step One: Convert mass to grams
Take the entered mass and multiply by the selected mass-unit factor to get grams.
mass in grams = mass × mass unit factor
For 500 g (factor 1): 500 × 1 = 500 g. For 500 kg (factor 1000): 500 × 1000 = 500,000 g.
Step Two: Convert volume to cubic centimeters
Take the entered volume and multiply by the selected volume-unit factor to get cm³.
volume in cm³ = volume × volume unit factor
For 200 cm³ (factor 1): 200 × 1 = 200 cm³. For 200 L (factor 1000): 200 × 1000 = 200,000 cm³.
Step Three: Divide to get density in g/cm³
Apply the core density formula.
density (g/cm³) = mass in grams ÷ volume in cm³
For the defaults: 500 ÷ 200 = 2.5 g/cm³.
Step Four: Convert to your chosen result unit
Divide by the density-unit conversion factor to express the result in your preferred unit.
density in chosen unit = density (g/cm³) ÷ density unit factor
For g/cm³ (factor 1): 2.5 ÷ 1 = 2.5 g/cm³. For kg/m³ (factor 0.001): 2.5 ÷ 0.001 = 2,500 kg/m³.
Common uses
Density comparisons come up constantly — identifying an unknown metal or mineral, checking whether a material will float or sink, calculating shipping weight from a known volume, or verifying that a manufactured part matches its specified material.