Poise

The poise (symbol P, /ˈpɔɪz/) is the unit of dynamic viscosity in the centimetre–gram–second system of units. It is named after Jean Léonard Marie Poiseuille.

The analogous unit in the International System of Units is the pascal-second (Pa·s):

The poise is often used with the metric prefix centi- because the viscosity of water at 20 °C is almost exactly 1 centipoise. A centipoise is one hundredth of a poise, equal to one millipascal-second (mPa·s) in SI units (1 cP = 10⁻³ Pa·s = 1 mPa·s).

The CGS symbol for the centipoise is cP. The abbreviations cps, cp, and cPs are sometimes seen.

Water has a viscosity of 0.00899 poises at 25 °C and a pressure of 1 atmosphere (0.00899 P = 0.899cP = 0.899 mPa·s).