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Dynamic Viscosity Converter

Convert fluid shear resistance and internal friction across Pascal-seconds (Pa·s), Poise (P), Centipoise (cP), and lb/(ft·s) with real-time bidirectional calculations.

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1,000 cP = 0.67197 lb/(ft·s)

lb/(ft·s) to Pa·s→

1 lb/(ft·s) = 1.48816 Pa·s

Dynamic Viscosity Reference Equivalents (1 Pascal-second)

Standard ratios measured against the base Pascal-second (Pa·s)

Reference Table

Unit Name	Symbol	Equivalent in 1 Pa·s	Quick Pair Page
Pascal-second	Pa·s	1 Pa·s = 1 Pa·s	Base Unit
Poise	P	1 Pa·s = 10 P	Pa·s to P →
Centipoise	cP	1 Pa·s = 1,000 cP	Pa·s to cP →
Pound per foot-second	lb/(ft·s)	1 Pa·s = 0.671969 lb/(ft·s)	Pa·s to lb/(ft·s) →

Dynamic Viscosity of Common Fluids Reference Chart

Lookup table of dynamic viscosities (internal shear resistance) at 20°C and standard atmospheric pressure

Lookup Matrix

Fluid / Substance	Centipoise (cP)	Pascal-second (Pa·s)	Poise (P)	lb/(ft·s)
Air (20°C, 1 atm)	0.0182 cP	0.0000182 Pa·s	0.000182 P	0.0000122 lb/(ft·s)
Acetone (Pure)	0.32 cP	0.00032 Pa·s	0.0032 P	0.000215 lb/(ft·s)
Pure Liquid Water (20°C)	1.002 cP	0.001002 Pa·s	0.01002 P	0.000673 lb/(ft·s)
Whole Milk	2.0 cP	0.0020 Pa·s	0.020 P	0.001344 lb/(ft·s)
Blood (Human Body Temp 37°C)	3.5 cP	0.0035 Pa·s	0.035 P	0.002352 lb/(ft·s)
Ethylene Glycol (Pure)	16.1 cP	0.0161 Pa·s	0.161 P	0.01082 lb/(ft·s)
Olive Oil (Extra Virgin)	84.0 cP	0.0840 Pa·s	0.840 P	0.05645 lb/(ft·s)
SAE 30 Motor Oil (Warm)	200.0 cP	0.2000 Pa·s	2.000 P	0.13439 lb/(ft·s)
Pure Castor Oil	985.0 cP	0.9850 Pa·s	9.850 P	0.66189 lb/(ft·s)
Pure Glycerol (Glycerin)	1,412.0 cP	1.4120 Pa·s	14.12 P	0.94883 lb/(ft·s)
Honey (Clover)	10,000.0 cP	10.00 Pa·s	100.0 P	6.7197 lb/(ft·s)
Sour Cream / Mayonnaise	50,000.0 cP	50.00 Pa·s	500.0 P	33.599 lb/(ft·s)
Peanut Butter / Toothpaste	250,000.0 cP	250.00 Pa·s	2,500.0 P	167.99 lb/(ft·s)
Industrial Molasses (Heavy)	1,000,000.0 cP	1,000.00 Pa·s	10,000.0 P	671.97 lb/(ft·s)

Rheology & Fluid Mechanics

Dynamic Viscosity: Shear Stress, Newton's Law & Rheological Conversion Standards

Authoritative guide to fluid shear resistance, Newtonian vs non-Newtonian behavior, viscometer measurement, and SI unit conversions.

Newton's Viscosity Law & Shear Stress

Dynamic viscosity represents the ratio between applied shear stress and the resulting shear strain rate in a laminar moving fluid layer:

τ = μ · (du / dy) ⟹ μ = τ / γ̇

Newtonian Viscosity Law (τ = Shear Stress in Pa, μ = Dynamic Viscosity in Pa·s, du/dy = γ̇ = Shear Strain Rate in s⁻¹)

In Newtonian fluids (water, air, alcohol, light oils), dynamic viscosity μ remains completely independent of shear rate. In non-Newtonian fluids (paint, blood, ketchup, polymer melts), viscosity varies dynamically with agitation, shear thinning, or thickening.

SI, CGS, and Imperial Viscosity Standards

Industrial rheologists and laboratory chemists bridge multiple historical unit scales:

SI Metric Standard: Pa·s & mPa·s

1 Pascal-second represents 1 N·s/m². Because 1 Pa·s is quite thick (like castor oil), scientific literature predominantly uses millipascal-seconds (mPa·s). Conveniently, 1 mPa·s = 1 cP exactly.

CGS Standard: Centipoise (cP)

1 Poise (P) = 1 dyne·s/cm² = 0.1 Pa·s. 1 Centipoise = 0.01 P = 0.001 Pa·s. Centipoise remains the universal standard in paint manufacturing, oil refining, and pharmaceutical formulation.

Reynolds Number & Laminar-Turbulent Transition

Dynamic viscosity serves as the denominator in the dimensionless Reynolds Number (Re), which predicts whether fluid flow inside a pipe is orderly laminar or chaotic turbulent:

Re = (ρ · v · D) / μ = (v · D) / ν

Reynolds Number Formula (Re < 2,300 indicates Laminar Flow; Re > 4,000 indicates Turbulent Flow)

High dynamic viscosity dampens turbulent eddy formation, maintaining laminar streamlines in heavy oils and syrups even at high pumping velocities.

About Dynamic Viscosity Units & Formulas

1 Pa·s = 10 Poise = 1,000 Centipoise (cP).

Pascal-secondPa·s

SI unit of dynamic viscosity

PoiseP

CGS unit (1 P = 0.1 Pa·s)

CentipoisecP

Water dynamic viscosity at 20°C ≈ 1.002 cP

Pound per foot-secondlb/(ft·s)

Imperial dynamic viscosity

FREQUENTLY ASKED QUESTIONS

Dynamic Viscosity Converter FAQs

Frequently asked questions regarding dynamic viscosity conversion metrics, formulas, and real-world calculation standards

How do you convert Centipoise (cP) to Pascal-seconds (Pa·s)?

To convert Centipoise (cP) to Pascal-seconds (Pa·s), divide by 1,000 (or multiply by 0.001): Pa·s = cP × 0.001.

Physical Examples:

Liquid water at 20°C has a viscosity of 1.002 cP: 1.002 × 0.001 = 0.001002 Pa·s (1.002 mPa·s).
Glycerin has a viscosity of 1,412 cP: 1,412 × 0.001 = 1.412 Pa·s.
Reverse Conversion: Multiply Pascal-seconds by 1,000 to get Centipoise (2.5 Pa·s × 1,000 = 2,500 cP).

What is dynamic (absolute) viscosity in physics?

Dynamic viscosity (μ or η) is the measure of a fluid's internal resistance to gradual deformation by shear stress or extensional stress.

Newton's Law of Viscosity: τ = μ × (du / dy), where τ is the shear stress (N/m² or Pa) and du/dy is the velocity gradient (rate of shear strain in s⁻¹).
SI Unit: Pascal-second (Pa·s), which equals 1 N·s/m² = 1 kg/(m·s).
CGS Unit: Poise (P) and Centipoise (cP), named in honor of Jean Léonard Marie Poiseuille. 1 Poise = 0.1 Pa·s; 1 cP = 1 mPa·s.

What is the difference between dynamic and kinematic viscosity?

Dynamic viscosity (μ) measures internal fluid friction under applied external shear force (independent of gravity), expressed in Pa·s or Centipoise.

Kinematic viscosity (ν) measures fluid flow under the influence of Earth's gravity, calculated by dividing dynamic viscosity by the fluid's mass density (ν = μ ÷ ρ), expressed in m²/s or Centistokes (cSt).

Why does water have a dynamic viscosity of almost exactly 1 cP?

When the metric CGS viscosity unit was standardized in the 19th century, the viscosity of liquid water at 20°C (room temperature) was chosen as the baseline benchmark of 1.00 Centipoise (1.002 cP = 0.001002 Pa·s). This makes Centipoise an intuitive scale where any fluid viscosity is easily compared against liquid water.

How does temperature affect dynamic viscosity in liquids vs gases?

Temperature exerts opposite effects on liquid and gas viscosity:

Liquids: Dynamic viscosity decreases drastically as temperature rises. Heating weakens cohesive intermolecular attractive forces (hydrogen bonds and van der Waals attractions), allowing molecules to slip past one another with less resistance (e.g., motor oil thins when hot).
Gases: Dynamic viscosity increases with rising temperature. In gases, viscosity is caused by momentum exchange during molecular collisions. Higher temperature speeds up molecular velocities, causing more frequent collisions and higher shear resistance.