๐งด Viscosity Converter
Convert between pascal-seconds (Paยทs), poise (P), and centipoise (cP) โ units of a liquid's dynamic viscosity โ in real time. Useful for chemistry and engineering homework, or checking product specs for lubricants and paints.
How to use
- Enter a value into any viscosity unit field (Paยทs, P, or cP).
- The converted values appear instantly in the other unit fields.
How the calculation works
Viscosity measures how much a liquid resists flowing โ the resistance that arises when layers of liquid slide past one another. Its SI unit is the pascal-second (Paยทs). The poise (P) is the CGS unit, 1 P = 0.1 Paยทs. Everyday liquids are usually described in centipoise (cP), a hundredth of that, equal to 1 mPaยทs. Water at around 20ยฐC is almost exactly 1 cP, so a figure in cP reads intuitively as "how many times thicker than water". Viscosity is strongly temperature-dependent. Most liquids get runnier as they warm up, so a viscosity value only means something alongside the temperature it was measured at.
Worked example
A liquid of 1,000 cP in Paยทs 1,000 ร 0.001 = 1 Paยทs In poise that is 10 P โ about a thousand times thicker than water (about 1 cP). Going the other way, 0.05 Paยทs is 0.05 รท 0.001 = 50 cP.
Things to be aware of
- This converts dynamic viscosity. Kinematic viscosity (centistokes, cSt) is a different quantity โ dynamic viscosity divided by density.
- Viscosity changes a lot with temperature; compare values measured at the same temperature.
- Paint and ketchup are non-Newtonian fluids whose viscosity changes with how fast they are stirred, so a single number does not capture them.
- Motor oil grades such as "10W-30" are viscosity grades and do not map directly onto these units.
FAQ
What's the viscosity of water?
Water at room temperature (around 20ยฐC) has a viscosity of about 1 cP (0.001 Paยทs) โ a handy reference point for gauging other liquids.
What's the difference between poise and centipoise?
1 poise (P) equals 100 centipoise (cP). cP is the unit most commonly used for everyday liquid viscosity.
Does this handle kinematic viscosity (centistokes)?
No โ this tool only handles dynamic viscosity. Kinematic viscosity also depends on density, so it needs a separate conversion.