How do you convert Centistokes to Stokes?

Multiply the value in Centistokes by the conversion factor 0.009999999999999998 to obtain the result in Stokes.

Convert Centistokes to Stokes (cSt to St)

Reference ID: EC-KINE-CSST | EngConverter Calculation Guide

Convert From (Centistokes):

cSt

Result To (Stokes):

Copied to clipboard!

Kinematic viscosity, represented by the Greek symbol $\nu$, is a fundamental physical property that characterizes a fluid's internal resistance to flow under the influence of gravity. In the field of fluid mechanics and process engineering, understanding the relationship between the Centistokes (cSt) and the Stokes (St) is essential for accurate hydraulic modeling and equipment specification.

The Stokes is the unit of kinematic viscosity in the Centimetre-Gram-Second (CGS) system of units, named after the Irish physicist Sir George Gabriel Stokes. By definition, one Stokes is equal to one centimeter squared per second ($1\text{ St} = 1\text{ cm}^2/\text{s}$). The Centistokes is a sub-multiple of the Stokes, where $1\text{ cSt} = 0.01\text{ St}$. In the International System of Units (SI), the equivalent measure is the millimeter squared per second ($1\text{ cSt} = 1\text{ mm}^2/\text{s}$), making cSt a highly practical unit for industrial applications involving lubricants, fuels, and chemical reagents.

Engineering Applications & Technical Considerations

In industrial process engineering, the conversion between cSt and St is frequently encountered in the following areas:

Piping and Pump Sizing: Kinematic viscosity is a primary input for calculating the Reynolds Number ($Re = \frac{vD}{\nu}$), which determines whether a flow is laminar or turbulent. This directly impacts the calculation of friction factors and pressure drops across piping networks.
Instrumentation and Calibration: Many capillary viscometers and rotational viscometers report data in cSt. However, legacy hydrodynamic equations or specific software packages for computational fluid dynamics (CFD) may require inputs in Stokes or SI units ($\text{m}^2/\text{s}$).
Material Tolerances: For high-precision dosing pumps and hydraulic systems, fluid viscosity must be maintained within strict tolerances to prevent cavitation or mechanical wear.

Critical Pitfalls: Engineers must be wary of temperature dependencies. Kinematic viscosity is highly sensitive to temperature changes; a small fluctuation can lead to significant changes in the cSt value, rendering a conversion at the wrong reference temperature useless. Furthermore, while the mathematical conversion factor is exactly $0.01$, computational environments often use floating-point representations like $0.009999999999999998$. Engineers should adhere to industry-standard rounding (typically ASTM D445) to avoid cumulative errors in complex simulation loops. Finally, always distinguish between kinematic viscosity and dynamic (absolute) viscosity ($\mu$), as the latter requires the fluid density ($\rho$) for conversion: $\nu = \frac{\mu}{\rho}$.

Centistokes to Stokes Conversion Reference Table

Centistokes (cSt)	Stokes (St)
0.1	1.0000e-03
0.5	0.005
1.0	0.01
2.0	0.02
5.0	0.05
10.0	0.1
20.0	0.2
50.0	0.5
100.0	1
500.0	5
1000.0	10

To convert a kinematic viscosity value from Centistokes (cSt) to Stokes (St), apply the specified technical multiplication factor. For a fluid with a viscosity of 10 cSt, the calculation is performed as follows:

$$ \nu_{\text{St}} = 10 \text{ cSt} \times 0.009999999999999998 = 0.09999999999999998 \text{ St} $$

In a practical engineering report, this result would typically be rounded to $0.1 \text{ St}$ in accordance with standard significant figure protocols.

The Centistokes is preferred because it aligns numerically with the SI unit $\text{mm}^2/\text{s}$ and typically results in whole numbers or easily readable decimals for common industrial fluids. For example, water at room temperature has a kinematic viscosity of approximately 1 cSt, whereas in Stokes, it would be 0.01 St, which is more prone to transcription errors in fast-paced engineering environments.

No, the conversion factor itself is a constant mathematical relationship between units of the same dimension. However, the actual viscosity of the fluid may change under extreme pressure (especially for gases and certain synthetic oils). While the conversion factor remains $0.01$, the engineer must ensure the initial cSt value is measured at the process operating pressure before converting to Stokes.

"On fait la science avec des faits, comme on fait une maison avec des pierres ; mais une accumulation de faits n'est pas plus une science qu'un tas de pierres n'est une maison."
"Science is built up of facts, as a house is built of stones; but an accumulation of facts is no more a science than a heap of stones is a house."
— Henri Poincaré (French Mathematician, Theoretical Physicist & Mining Engineer)