Convert oil viscosity between centistokes, stokes, mm²/s, m²/s, centipoise, poise, Pa·s, and mPa·s. Use density to estimate the relationship between kinematic viscosity and dynamic viscosity for motor oil, gear oil, hydraulic oil, and lubricants.
cSt to mm²/s:
1 cSt = 1 mm²/s
St to cSt:
1 St = 100 cSt
cP to mPa·s:
1 cP = 1 mPa·s
cSt to cP:
cP = cSt × density in g/cm³
Oil viscosity conversions are useful for motor oil, gear oil, transmission fluid, hydraulic oil, differential fluid, industrial lubricants, oil analysis reports, technical data sheets, and comparing kinematic and dynamic viscosity values.
Use this converter for unit conversion only. Always follow the oil grade and specification recommended by the engine, equipment, or vehicle manufacturer.
Your result shows the entered viscosity converted into the selected unit. The converter also displays reference values for cSt, St, mm²/s, cP, mPa·s, and Pa·s.
Oil viscosity depends strongly on temperature. A viscosity value measured at 40°C is not the same as a viscosity value measured at 100°C. SAE oil grades such as 0W-20, 5W-30, 10W-40, and 75W-90 are performance classifications, not simple unit conversions.
Multiply cSt by density in g/cm³. For example, 100 cSt with oil density 0.87 g/cm³ is about 87 cP.
Yes. For kinematic viscosity, 1 cSt equals 1 mm²/s.
Yes. For dynamic viscosity, 1 cP equals 1 mPa·s.
Not exactly. 5W-30 is an SAE oil grade, not a single viscosity value. Actual cSt depends on the oil formula and test temperature.
Oil gets thinner as temperature rises and thicker as temperature falls, so viscosity values should be compared at the same temperature.