Viscosidade Cinemática
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
ν = μ/ρ
About this calculator
The Kinematic Viscosity Calculator determines the kinematic viscosity (ν) of a fluid from dynamic viscosity (μ) and density (ρ). The formula used is ν = μ / ρ. This quantity is fundamental in fluid mechanics, as it relates internal flow resistance to fluid inertia.
Operation is simple: enter the dynamic viscosity (in Pa·s or cP) and density (in kg/m³ or g/cm³). The calculator automatically converts units if needed and returns the result in m²/s or St (Stokes). It is useful for comparing fluids under different temperature and pressure conditions.
Use this calculator in engineering projects involving fluid flow, such as pipe sizing, lubrication systems, and aerodynamic analysis. It is also applicable in laboratories to characterize oils, fuels, and other liquids. Kinematic viscosity is essential for calculating the Reynolds number, which determines whether flow is laminar or turbulent.
Cautions: ensure input units are consistent. Dynamic viscosity and density must be on the same scale (SI or CGS). Remember that kinematic viscosity varies strongly with temperature; for accurate results, measure or obtain values at operating conditions. Do not confuse dynamic viscosity with kinematic viscosity.
Frequently asked questions
What is the difference between dynamic and kinematic viscosity?
Dynamic viscosity measures flow resistance due to internal forces, while kinematic viscosity also considers fluid density. Kinematic is dynamic divided by density.
Can I use this calculator for gases?
Yes, as long as you have the dynamic viscosity and density values for the gas under the desired conditions. Gases have higher kinematic viscosity than liquids due to low density.
How does temperature affect kinematic viscosity?
In liquids, kinematic viscosity decreases with increasing temperature. In gases, it increases with temperature. Always use values measured at the operating temperature.
What units are supported?
The calculator accepts Pa·s, cP, kg/m³, and g/cm³. Results are displayed in m²/s and St (Stokes). Automatic conversions are performed internally.
What is the Reynolds number and how does it relate?
The Reynolds number (Re) is calculated as Re = V*L/ν, where V is velocity, L a characteristic length, and ν kinematic viscosity. It indicates whether flow is laminar (low Re) or turbulent (high Re).