What does centipoise mean?
A centipoise (symbol cP) is a unit of measurement for dynamic viscosity — a fluid's resistance to flow — equal to one hundredth of a poise, or exactly one millipascal-second. The unit takes its name from the French physicist Jean Léonard Marie Poiseuille, whose pioneering work on blood flow in narrow tubes laid the foundations of the study of fluid viscosity. Because water at room temperature has a viscosity of very nearly one centipoise, the unit offers an intuitive baseline: honey runs to thousands of centipoise, olive oil to tens, while air sits at a tiny fraction. Centipoise remains firmly embedded in practical fields such as food processing, cosmetics, pharmaceuticals, coatings, and petroleum engineering, where product consistency is specified in these terms. Although the modern SI system favours the millipascal-second, the two units are identical in value, so centipoise persists as the familiar, human-scaled way engineers and formulators talk about thickness.
nounA centipoise is a unit of dynamic viscosity equal to one hundredth of a poise; water at 20 °C has a viscosity of approximately one centipoise.
- A CGS-derived unit of dynamic viscosity equal to one hundredth of a poise, equivalent to one millipascal-second.
"The syrup's viscosity was measured at several thousand centipoise, far thicker than water's single centipoise."
"At room temperature, water has a viscosity of about one centipoise, while honey measures closer to ten thousand."
"The paint was thinned with solvent until its viscosity dropped below 100 centipoise, allowing it to spray evenly."
Both the regular plural "centipoises" and the invariant "centipoise" (as in "200 centipoise") are accepted in technical writing; the invariant form follows common practice for units of measurement.
"The two formulations differed by only a few centipoises in measured viscosity."
Water clocks in at almost exactly 1 centipoise — making it the everyday benchmark scientists reach for when describing how thick any liquid feels.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of centipoise
The word centipoise combines the metric prefix centi- (from Latin centum, meaning "hundred") with poise, the CGS unit of viscosity introduced in honour of the French physiologist and physicist Jean Léonard Marie Poiseuille (1797–1869), who studied laminar fluid flow in tubes. The term emerged in scientific usage in the late nineteenth or early twentieth century alongside the adoption of the CGS system, and it entered English through technical literature on rheology and fluid mechanics. Its cognates are essentially other words built from centi-, such as centimetre and centigram.
How centipoise is actually used
Used almost exclusively in technical and scientific contexts — chemistry, engineering, food science, and industrial manufacturing. The unit is often treated as invariant in technical writing (e.g. "50 centipoise"), though the regular plural "centipoises" also occurs. It belongs to the older CGS system but remains widely used in industry, especially for reporting viscosity of fluids like oils, syrups, paints, and biological fluids.
Easily confused with centipoise
A poise is the larger CGS unit of viscosity (dyne-second per square centimetre), and a centipoise is simply one hundredth of it.