Kinetic viscosity is the ratio of the dynamic viscosity of a liquid to the density ρ of the fluid at the same temperature. The unit is (m^2)/s. It is represented by the lowercase letter v. Note: The unit that has been used is St. The relationship between St and (m^2)/s is: 1(m^2)/s=10^4St=10^6cSt. (where "cSt" is read as "centistokes") The flowing liquid is regarded as many liquid layers moving parallel to each other, and the speed of each layer is different, forming a velocity gradient (dv/dx), which is the basic characteristic of flow.

Formula v = m/p

v = kinematic viscosity [m²s^-1]

m = dynamic viscosity [Nsm^-2]

ρ = density [kgm^-3]