The primary application of the continuity equation or equation of continuity is involved in the field of Hydrodynamics, Electromagnetism, Aerodynamics, and Quantum Mechanics. The eqn of continuity forms the elemental rule of Bernoulli's Principle. It is also related to the Aerodynamics principle with its applications.

The differential form of the continuity eq. is used to find out the consistency of Maxwell's Equation. Aside from, the differential form of the continuity equation is also used in Electromagnetism.

Continuity eq. is used to examine the consistency of Schrodinger Eq.

Common and Special Theory of Relativity, Noether's Theorem, also used the Continuity equation.