Density
Density is a core engineering term. Definition, usage notes, and a practical example.
Definition
Density is mass per unit volume.
Why it matters
It affects weight, inertia, buoyancy, and logistics cost.
How it is used
In a design check, first define the relevant load, dimension, material, or flow condition. Then interpret this term by its role in the formula and compare it with limits.
Design note
Density directly affects part mass, center of gravity, and inertia loads in moving systems. A lower density material can reduce total weight for the same geometry, but stiffness, manufacturability, cost, and availability must be checked at the same time. For fluids, density may change with temperature, so pressure-loss or buoyancy calculations should state the operating temperature.
Density = Mass / Volume
For the same volume, a steel part can be about three times heavier than aluminum.
Related calculators and resources
Formulas
Density = Mass / Volume