A c.g.s. unit of measure of the kinematic viscosity of a fluid expressed as the ratio of the viscosity, μ, in poise divided by the density, ρ, in grams per cubic centimetre:
The units of centistokes, cSt, are more commonly used where 1 cSt is equal to 10−6 m2 s−1. The kinematic viscosity of water is exactly 1 cSt at 20.2ºC.