Mass Flow Rate Calculator

Calculate ṁ = ρQ from density and volumetric flow rate, or from density, velocity, and pipe geometry.

Fluid Mechanics I

Common fluids — click to auto-fill density

Density is always required. Then provide either the volumetric flow rate Q, or velocity V with pipe geometry.

Fluid density ρ (kg/m³)

Volumetric flow rate Q (m³/s)

Main equation:

ṁ = ρ × Q = ρ × A × V

Where:

For steady incompressible flow, mass flow rate is constant along a pipe (continuity equation: ρ₁A₁V₁ = ρ₂A₂V₂, and since ρ is constant, A₁V₁ = A₂V₂).