Viscosity Converter

How viscosity conversion works

This converts dynamic viscosity — a fluid's internal resistance to flow — between the SI unit (Pascal-seconds) and the older CGS-system units (poise, centipoise) still common in chemistry and industry. This is a different quantity from kinematic viscosity (which also factors in the fluid's density), so the two shouldn't be confused.

Reference points

• Water at room temperature has a viscosity of almost exactly 1 centipoise (0.001 Pa·s)
• Honey is roughly 2,000–10,000 centipoise, depending on temperature
• 1 poise = 100 centipoise = 0.1 Pa·s

The relationships used

Pascal-seconds are the base. The tool uses 1 poise = 0.1 Pa·s and 1 centipoise = 0.001 Pa·s, so 1 cP is also exactly 1 mPa·s. Output shows up to eight decimals, which is more than the other converters, because viscosities in Pa·s are often small decimals. The default converts 1 cP to Pa·s.

Worked examples

• 1 cP = 0.001 Pa·s (the default).
• 0.89 cP = 0.00089 Pa·s.
• 1,500 cP = 1.5 Pa·s.
• 5,000 cP = 50 poise.
• 2 Pa·s = 2,000 cP.
• 1 poise = 0.1 Pa·s, and 0.5 poise = 50 cP.

Limits

This converter handles dynamic viscosity only. Kinematic viscosity (centistokes, stokes, m²/s) needs the fluid's density as well and is not offered. The tool cannot correct for temperature, so use the value measured at the temperature you care about. A value under 0.000000005 of the target unit rounds to zero: 0.000000001 cP is shown as 0 Pa·s. Negative numbers are accepted as typed.

More conversions

5 poise is 500 cP, 2.5 cP is 0.025 P, 1 Pa·s is 10 poise, and 350 cP is 0.35 Pa·s. A centipoise is the same size as a millipascal-second, so converting cP to Pa·s is just a division by 1,000.

These three units all measure dynamic viscosity. Kinematic viscosity, in centistokes or m²/s, is the dynamic viscosity divided by the density of the fluid, so it cannot be converted with this tool alone. Viscosity also depends strongly on temperature, so a converted figure holds only at the temperature it was measured.