Kinematic Viscosity Conversion Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/10/2026
To convert a kinematic viscosity, it is reduced to m²/s, then converted into the desired unit: 1 stokes = 0.0001 m²/s. Example: a viscosity of 2 stokes equals 0.0002 m²/s.
Explanation
Kinematic viscosity measures a fluid's resistance to flow under its own weight, by referring its dynamic viscosity to its density (ν = µ/ρ — see our dynamic and kinematic viscosity relationship calculator for that physical calculation). Its SI unit is the square meter per second (m²/s), but industrial use and oil or lubricant data sheets almost always use the stokes (St) or, more commonly still, the centistokes (cSt): 1 St = 1 cm²/s = 0.0001 m²/s, and 1 cSt = 0.01 St = 1 mm²/s. As a benchmark, water at 20°C has a kinematic viscosity close to 1 cSt, while a motor oil is typically between 20 and 200 cSt depending on its temperature. This calculator converts only between the units of KINEMATIC viscosity; for dynamic viscosity (pascal-second, poise), see our dynamic viscosity conversion calculator.
Example: a viscosity of 2 stokes
Inputs
Value: 2. Starting unit: St. Target unit: m²/s.
Calculation
1 stokes = 0.0001 m²/s, by definition (1 cm²/s converted to m²/s). So multiply by 0.0001. 2 × 0.0001 = 0.0002 m²/s.
Result
A viscosity of 2 stokes equals 0.0002 m²/s.
Frequently asked questions
What is the difference between dynamic viscosity and kinematic viscosity?
Dynamic viscosity (in pascal-second) measures a fluid's internal resistance to shear, while kinematic viscosity (in m²/s) refers it to the fluid's density (ν = µ/ρ). Two fluids with the same dynamic viscosity can have different kinematic viscosities if they do not have the same density. See our dynamic viscosity conversion calculator for the other quantity.
Why are motor oils indexed in centistokes?
Oil classification standards (such as ISO VG) define their grade directly by their kinematic viscosity in centistokes at a reference temperature (generally 40°C), because it is the most practical quantity to measure and compare between lubricants for industrial use.
What is the kinematic viscosity of water?
At 20°C, water has a kinematic viscosity of about 1 centistokes (1 mm²/s), which makes it a convenient reference for comparing other fluids: a motor oil, for example, is 20 to 200 times more viscous.
Does this calculator also convert to dynamic viscosity (Pa·s, poise)?
No, deliberately: dynamic viscosity and kinematic viscosity are two different physical quantities that should never be mixed in the same unit converter. Use our dedicated dynamic viscosity conversion calculator, or our dynamic/kinematic relationship calculator to physically go from one to the other via density.