The poise is often used with the metric prefixcenti- because the viscosity of water at 20°C is almost exactly 1 centipoise. A centipoise is one one-hundredth of a poise, and one millipascal-second (mPa·s) in SI units. (1 cP = 10−3 Pa·s = 1 mPa·s)
The centipoise is properly abbreviated cP, but the alternative abbreviations cps, cp, and cPs are also commonly seen.
Water has a viscosity of 0.00899 poise at 25 °C and a pressure of 1 atmosphere. (0.00899 P = 0.899cP = 0.899 mPa·s)