Viscosity Converter

1. Enter the value you want to convert.
2. Choose the from unit.
3. Choose the to unit.
4. Read the result and the conversion rate.

Here is what each result means:

Viscosity is a fluid's resistance to flow. A thin fluid like water pours easily and has a low viscosity, while a thick one like honey resists and has a high viscosity. This page handles dynamic viscosity, the ratio of shearing stress to the rate at which a fluid deforms, which is what most datasheets quote.

The SI unit is the pascal-second. Far more common in practice is the centipoise, because water at room temperature is very close to 1 centipoise, making it a natural reference. One centipoise equals one millipascal-second, so the two scales line up neatly. The poise is one hundred centipoise, and imperial units like pound-force seconds per square foot appear in older engineering work.

This converter bridges every unit through the pascal-second. It multiplies your value by the number of pascal-seconds in its unit, then divides by the number in the target unit. Because each unit has a fixed value, the conversions are exact and never change.

Dynamic viscosity should not be confused with kinematic viscosity, which is dynamic viscosity divided by density and is measured in stokes or square metres per second. This converter handles dynamic viscosity only, the kind quoted in centipoise and pascal-seconds.

It converts through the pascal-second, the SI unit of dynamic viscosity.

1. Your value is multiplied by its unit's value in pascal-seconds.
2. That gives the viscosity in pascal-seconds, the common base.
3. Dividing by the target unit's value gives the result.

For related fluid quantities, see the density converter and the pressure converter.

Convert 1 cP to pascal-seconds.

Result: 1 centipoise is 0.001 Pa.s, the same as 1 millipascal-second. That is the viscosity of water at about 20 degrees Celsius, the reference most fluids are compared against.

Every unit has a fixed value in pascal-seconds.

The centipoise and millipascal-second are identical, both one thousandth of a pascal-second, which is why fluids are so often quoted in centipoise. The imperial pound-force second per square foot is a large unit, at nearly 48 pascal-seconds.

Viscosity spans a huge range, from air to tar.

Comparing fluids this way shows the scale involved. Water at 1 centipoise is the reference, honey is thousands of times thicker, and gases like air are far thinner. Viscosity also falls sharply as most liquids warm, so a quoted figure always assumes a temperature.

The Two Units

The ratio between the from-unit and to-unit sets the result; each has a fixed value in Pa.s.

Poise Versus Pascal

One poise is 0.1 pascal-seconds, and one centipoise is 0.001, an easy factor to slip.

The Unit System

Imperial units like lbf.s/ft2 are far larger than metric ones, giving very different numbers.

Engineering

Convert a fluid viscosity between centipoise and pascal-seconds for a calculation.

Manufacturing

Match a specification in poise with a datasheet in centipoise or millipascal-seconds.

Older References

Turn an imperial viscosity from an older text into modern SI units.

1. Confusing Dynamic and Kinematic

This is dynamic viscosity in pascal-seconds. Kinematic viscosity, in stokes, is a different quantity.

2. Slipping the Poise Factor

A poise is 0.1 pascal-seconds and a centipoise 0.001. Missing this gives a hundred-fold error.

3. Ignoring Temperature

Viscosity changes a lot with temperature. A converted value assumes the same temperature as the input.

4. Wrong Direction

Check which unit is the from and which is the to; swapping them inverts the result.

5. Assuming Water Is Exactly 1 CP

Water is close to 1 centipoise near 20 degrees, but the exact figure shifts with temperature.

Conversions use fixed factors relative to the pascal-second.

About 1 centipoise, or 0.001 pascal-seconds, near 20 degrees Celsius. This makes water the standard reference for comparing fluids.

1,000. So 0.5 pascal-seconds is 500 centipoise. One centipoise equals one millipascal-second.

Dynamic viscosity, in pascal-seconds, measures resistance to shear. Kinematic viscosity, in stokes, is dynamic viscosity divided by density.

Yes. One centipoise equals one millipascal-second exactly, which is why the two are used interchangeably in practice.

Multiply poise by 0.1. So 10 poise is 1 pascal-second. A poise is one hundred centipoise.

Warmer liquids flow more easily, so their viscosity falls, often sharply. A quoted viscosity always assumes a specific temperature.

Motor and cooking oils range from tens to hundreds of centipoise at room temperature, far thicker than water but thinner than honey.

Centipoise is the most common for liquids, since water is about 1 centipoise. Pascal-seconds and millipascal-seconds are the SI equivalents.

No. The calculation runs in your browser and nothing you enter is stored or sent anywhere, unless you choose Save, which keeps the result only on this device.

• Viscosity (Wikipedia).
• Poise (unit) (Wikipedia).
• Pascal-second (Wikipedia).