Poise-Stokes Converter. Convert between dynamic viscosity and kinematic viscosity using this Poise-Stokes Converter. Enter the dynamic viscosity (η) in poise or centipoise and the fluid density (ρ) to get the kinematic viscosity (ν) in stokes or centistokes — or work in reverse. The tool applies the formula ν = η / ρ so you can switch between viscosity types for any fluid. Also try the Pipe Flow Calculator.
Have you ever wondered how the flow of a fluid changes when you switch between different viscosity units? The poise-stokes converter delivers the essential insight you need: it seamlessly translates between dynamic viscosity (poise) and kinematic viscosity (stokes), unlocking answers about how much force is required for a fluid to move at a particular speed or how to describe the speed of the fluid due to an applied force. Engineers, scientists, and chemists rely on these conversions to calibrate machines, blend mixtures, design hydraulic systems, and ensure processes are both efficient and safe. If you’ve ever faced frustration trying to compare viscosity values across formulas, standards, or different measurement systems, this tool removes the guesswork and enhances the accuracy of every calculation you make. See also our Orifice Flow Calculator.
To master fluid properties, it’s vital to grasp the difference and relationship between poise and stokes, and to understand how dynamic viscosity and kinematic viscosity interact. The poise-stokes converter thrives on this distinction, allowing you to confidently convert between units in a variety of scientific, technical, and industrial contexts.
Poise measures dynamic viscosity, whereas stokes measures kinematic viscosity. The key difference is that dynamic viscosity quantifies the effort required to move a fluid (how resistant to flow it is), while kinematic viscosity describes how quickly it flows due to that effort, taking material density into account.
To convert poise to stokes or vice versa, you need to know the density of your medium. This key property closes the gap between dynamic and kinematic viscosity:
Always confirm both viscosity and density use compatible measures to avoid conversion mistakes.
The calculator stands on a scientific foundation: the standard relationship between dynamic viscosity, density, and kinematic viscosity. Here you’ll find the formulas, step-by-step conversion problems, and handy charts for the most common viscosity needs.
To convert poise to stokes:
Kinematic viscosity(ν)in stokes equals dynamic viscosity(η)in poise divided by density(ρ)in grams per cubic centimeter.
$$
\
u = \frac{\eta}{\rho}
$$
where:
\( \
u \) = kinematic viscosity (St)
\( \eta \) = dynamic viscosity (P)
\( \rho \) = density (g/cm^3)
$$ \eta = \rho \times \
u $$$$ \
u = \frac{\eta}{\rho} $$$$ \
u = \frac{10}{0.9982} $$$$ \
u = 10.018~St $$| Fluid | Density (g/cm³) | Calculated Kinematic Viscosity (St) |
|---|---|---|
| H2O (20°C) | 0.9982 | 10.02 |
| Petrodiesel | 0.85 | 11.76 |
| Olive Oil | 0.92 | 10.87 |
| Mercury | 13.6 | 0.735 |
Note: For the same dynamic viscosity (10 poise), kinematic viscosity dramatically decreases as density increases.
| Dynamic Viscosity (P) | Density (g/cm³) | Kinematic Viscosity (St) |
|---|---|---|
| 0.01 | 0.9982 | 0.0100 |
| 1.00 | 0.9982 | 1.002 |
| 10.0 | 0.9982 | 10.02 |
| 5.00 | 0.90 | 5.56 |
| 0.10 | 1.00 | 0.100 |
Below are the most common questions about the poise to stokes viscosity converter. These address foundational concepts, terminology, and address confusion between types of viscosity. You might also find our calculate Drag Force (Fd), Dynamic Pressure (½ρu²) & Velocity Squared (u²) — Drag Equation useful.
To convert poise to stokes:
Use the relationshipν = η / ρ.
Example: With η = 1 P and ρ = 1 g/cm³, then ν = 1 St.
No. Centipoise (cP) is a type of dynamic viscosity; centistokes (cSt) is a type of kinematic viscosity. While their magnitudes may coincide for water at 20°C (because density ≈ 1 g/cm³), for all other substances or conditions, you must factor in the density to convert.
Density links the two physical properties by adjusting for the property (its mass per unit volume) in the conversion. It's the ratio of dynamic viscosity to density that gives kinematic viscosity: ν = η / ρ.Accuracy depends on correct inputs: if your density is precise (matched to temperature, composition), the service yields results to the limits of the instrument or method used. This holds true for both manual calculation and digital poise-stokes converter usage.
Viscosity is measured in two ways. Dynamic (absolute) viscosity is measured in poise (P) or centipoise (cP) in the CGS system, and in pascal-seconds (Pa·s) in SI units. Kinematic viscosity is measured in stokes (St) or centistokes (cSt) in CGS, and in m²/s in SI units.
There is no fixed conversion between poise and stokes without knowing the fluid density, because they measure different things. The relationship is ν (St) = η (P) / ρ (g/cm³). For water at ~20°C with a density of ~1 g/cm³, 1 poise equals approximately 1 stokes.
Use the formula ν = η / ρ, where ν is kinematic viscosity in stokes, η is dynamic viscosity in poise, and ρ is density in g/cm³. Simply divide the poise value by the fluid's density in g/cm³ to get stokes.
Rearrange the formula to η = ν × ρ. Multiply the kinematic viscosity in stokes by the fluid's density in g/cm³ to obtain the dynamic viscosity in poise.
Kinematic viscosity is the ratio of dynamic (absolute) viscosity to fluid density. It describes how a fluid flows under gravity and is commonly used in applications like lubrication and fluid flow analysis. Its SI unit is m²/s, and the CGS unit is the stokes (St).
Dynamic viscosity (η) measures the internal resistance of a fluid to flow or shear stress — essentially how 'thick' it is. Kinematic viscosity (ν) accounts for the fluid's density and describes how quickly a fluid moves under gravity. Kinematic viscosity = dynamic viscosity / density.
Diesel has a density of approximately 0.85 g/cm³. Using η = ν × ρ: 0.025 St × 0.85 g/cm³ = 0.02125 poise, or about 2.125 centipoise (cP).
Use the formula η (cP) = ν (cSt) × ρ (g/cm³). Since 1 cP = 1 mPa·s and 1 cSt = 1 mm²/s, you can also write: η (in cP) = ρ (in kg/m³) × ν (in cSt) / 1000. Both expressions give the same result.