Dynamic Viscosity Converter
Pa·s · Poise · Centipoise (cP) · mPa·s · lb/(ft·s) · kg/(m·s)
Convert dynamic viscosity units instantly — Pascal-second, Poise, centipoise and more. Click any row in the conversion table to set it as the target unit.
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1 Pa·s = 1,000 cP = 10 P
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Water ≈ 1 cP at 20°C
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1 cP = 0.001 Pa·s = 1 mPa·s
About Dynamic Viscosity Units
Dynamic viscosity (absolute viscosity) quantifies a fluid's resistance to shear deformation — how hard you have to push to make it flow. It is fundamental in fluid mechanics, chemical engineering, food science, petroleum, and lubrication. The SI unit is Pascal-second (Pa·s), but centipoise (cP) remains widely used because water at 20°C has exactly 1 cP.
🔬 SI & CGS Units
The SI unit Pa·s = 1 kg/(m·s). The CGS unit Poise (P) = 0.1 Pa·s = 1 g/(cm·s). Centipoise (cP) = 0.01 P = 0.001 Pa·s = 1 mPa·s. cP is practical because water ≈ 1 cP, giving immediate intuition. mPa·s is numerically equal to cP and preferred in modern SI publications.
🇺🇸 Imperial & Engineering Units
lb/(ft·s) (pound per foot-second) is the US/Imperial unit. 1 lb/(ft·s) = 47.88 Pa·s = 47,880 cP — much larger than common fluid viscosities. In practice, US petroleum engineers use cP regardless of system since it is dimensionally convenient. kg/(m·s) is numerically identical to Pa·s.
Quick Viscosity Reference — Common Fluids at ~20°C
Air0.018 cP
Water (20°C)1.00 cP
Milk2–3 cP
Blood3–4 cP
Olive Oil80 cP
SAE 10W-30100–200 cP
Glycerine1,490 cP
Honey2,000–10,000 cP
Ketchup~50,000 cP
Peanut Butter~250,000 cP
Worked Examples
Water at 20°C
1 cP = 0.001 Pa·s
= 0.01 Poise
= 1 mPa·s
= 2.09×10⁻⁵ lb/(ft·s)
Reference fluid for all viscosity comparisons
= 1 mPa·s
= 2.09×10⁻⁵ lb/(ft·s)
Reference fluid for all viscosity comparisons
Glycerine at 20°C
1,490 cP = 1.49 Pa·s
= 14.9 Poise
= 1,490 mPa·s
= 0.03114 lb/(ft·s)
1,490× more viscous than water
= 1,490 mPa·s
= 0.03114 lb/(ft·s)
1,490× more viscous than water
SAE 30 Oil at 100°C
~10 cP = 0.01 Pa·s
= 0.1 Poise
= 10 mPa·s
= 2.09×10⁻⁴ lb/(ft·s)
Hot oil thins significantly
= 10 mPa·s
= 2.09×10⁻⁴ lb/(ft·s)
Hot oil thins significantly
Air at 20°C
0.018 cP = 1.8×10⁻⁵ Pa·s
= 1.8×10⁻⁴ Poise
= 0.018 mPa·s
= 3.76×10⁻⁷ lb/(ft·s)
55× less viscous than water
= 0.018 mPa·s
= 3.76×10⁻⁷ lb/(ft·s)
55× less viscous than water
Who Uses Dynamic Viscosity Conversion?
Petroleum Engineers
Convert crude oil and lubricant viscosities between cP (lab) and Pa·s (simulation). Oil viscosity varies 10,000-fold across grades and temperatures.
Food Scientists
Characterise flow properties of sauces, doughs and beverages in cP. Consistency affects pumping, filling, coating and consumer perception.
Pharmaceutical Engineers
Ensure syrups, injectables and topical formulations have correct viscosity for dosing accuracy, syringeability and shelf stability.
Lubrication Engineers
Select correct oil grades for bearings, gears and hydraulic systems. Convert between SAE viscosity grades and cP/Pa·s for fluid dynamics calculations.
Chemical & Process Engineers
Design pumps, pipelines and mixing equipment using viscosity in Pa·s. Higher viscosity requires more pumping power and different impeller designs.
Students & Researchers
Convert between unit systems when using international textbooks, simulation software and published experimental data in fluid mechanics.
Mental Math Tips
cP = mPa·s — they're the same number
1 cP = 1 mPa·s exactly. Never need to convert between them — just relabel. Water = 1 cP = 1 mPa·s = 0.001 Pa·s. Modern SI publications prefer mPa·s; older literature uses cP.
Pa·s ↔ cP: move the decimal 3 places
1 Pa·s = 1,000 cP. Pa·s → cP: multiply by 1,000 (move decimal right 3). cP → Pa·s: divide by 1,000 (move left 3). Example: glycerine at 1.49 Pa·s = 1,490 cP.
Poise is 10× Pa·s — a middle step
1 Pa·s = 10 Poise = 1,000 cP. Chain: Pa·s × 10 = Poise × 100 = cP. Quick: honey at ~5 Pa·s = 50 Poise = 5,000 cP. Air at 0.000018 Pa·s = 0.00018 Poise = 0.018 cP.
Frequently Asked Questions — Dynamic Viscosity Converter
Dynamic viscosity (absolute viscosity) measures a fluid's resistance to flow under an applied shear force — defined as the ratio of shear stress to shear rate: μ = τ/(du/dy). The SI unit is Pascal-second (Pa·s). High viscosity fluids (honey, motor oil) resist flow strongly; low viscosity fluids (water, petrol) flow easily.
Water has dynamic viscosity ≈ 1 cP (0.001 Pa·s) at 20°C. It decreases with temperature: at 0°C ≈ 1.79 cP, at 40°C ≈ 0.65 cP, at 100°C ≈ 0.28 cP. Water's 1 cP value is why centipoise is such a convenient reference unit — all aqueous solutions are multiples of this.
A centipoise (cP) = 1/100th of a Poise = 0.001 Pa·s = 1 mPa·s. Named after Jean Poiseuille. Water at 20°C ≈ 1 cP. cP is widely used in petroleum engineering, food science and pharmaceuticals. Numerically identical to mPa·s, so modern publications use mPa·s for SI compliance while older literature uses cP.
Dynamic viscosity (μ) measures resistance to shear — unit: Pa·s or cP. Kinematic viscosity (ν) = μ/ρ (divided by density) — unit: m²/s or centistoke (cSt). Use kinematic viscosity when gravity drives the flow; use dynamic viscosity when an external force drives flow. For water at 20°C: μ ≈ 1 cP, ρ = 998 kg/m³, so ν ≈ 1.004 cSt.
At ~20°C: Air = 0.018 cP · Water = 1 cP · Milk = 2–3 cP · Blood = 3–4 cP · Olive oil = 80 cP · SAE 10W-30 engine oil = 100–200 cP · Glycerine = 1,490 cP · Honey = 2,000–10,000 cP · Peanut butter ≈ 250,000 cP. Viscosity decreases with temperature for liquids and increases for gases.
Divide by 1,000: 1 cP = 0.001 Pa·s. The full chain: Pa·s × 10 = Poise × 100 = cP. Example: SAE 30 engine oil at 100°C ≈ 10 cP = 0.01 Pa·s = 0.1 Poise. Glycerine at 1,490 cP = 1.49 Pa·s = 14.9 Poise.
The Poise (P) is the CGS unit of dynamic viscosity. 1 Poise = 0.1 Pa·s = 100 cP = 1 g/(cm·s). Named after Jean Poiseuille. Centipoise (cP) is more commonly used because water = 1 cP is convenient. 1 Poise = 0.1 kg/(m·s) = 0.1 Pa·s.