centipoises (cP) to pound-force-seconds per square foot (lbf-s/ft2) conversion

1 cP = 0.00002088543 lbf-s/ft2lbf-s/ft2 → cP
Formula
1 cP = 0.00002088543 lbf-s/ft2

Understanding centipoises to pound-force-seconds per square foot Conversion

The centipoise (cP) is the metric-derived unit of dynamic viscosity where water is roughly 1 cP. The pound-force-second per square foot (lbf·s/ft²), also called the reyn's foot-based cousin, is the US customary/English-engineering unit of dynamic viscosity, and it is a very large unit — one lbf·s/ft² equals about 47,880 cP. Converting centipoises to lbf·s/ft² matters in American mechanical and petroleum engineering, where lubrication, bearing, and pipe-flow calculations are carried out entirely in customary units.

Conversion Formula

1 cP=0.00002088543 lbf-s/ft21\ \text{cP} = 0.00002088543\ \text{lbf-s/ft2}

To convert centipoises to pound-force-seconds per square foot, multiply by this factor:

lbf-s/ft2=cP×0.00002088543\text{lbf-s/ft2} = \text{cP} \times 0.00002088543

Step-by-Step Example

Convert 25 centipoises to pound-force-seconds per square foot.

lbf-s/ft2=25×0.00002088543=0.000522136 lbf-s/ft2\text{lbf-s/ft2} = 25 \times 0.00002088543 = 0.000522136\ \text{lbf-s/ft2}

How to Convert centipoises to pound-force-seconds per square foot

This conversion bridges metric lab readings and US customary engineering units.

  1. Take the centipoise value: Begin with the viscosity in cP, for example 25 cP.
  2. Multiply by 0.00002088543: This is the number of lbf·s/ft² in one centipoise.
  3. Compute the product: 25×0.00002088543=0.00052213625 \times 0.00002088543 = 0.000522136.
  4. State the result: 25 centipoises equals about 0.000522136 pound-force-seconds per square foot.

centipoises to pound-force-seconds per square foot conversion table

centipoises (cP)pound-force-seconds per square foot (lbf-s/ft2)
00
10.00002088543
20.00004177087
30.0000626563
40.00008354174
50.0001044272
60.0001253126
70.000146198
80.0001670835
90.0001879689
100.0002088543
150.0003132815
200.0004177087
250.0005221359
300.000626563
400.0008354174
500.001044272
600.001253126
700.00146198
800.001670835
900.001879689
1000.002088543
1500.003132815
2000.004177087
2500.005221359
3000.00626563
4000.008354174
5000.01044272
6000.01253126
7000.0146198
8000.01670835
9000.01879689
10000.02088543
20000.04177087
30000.0626563
40000.08354174
50000.1044272
100000.2088543
250000.5221359
500001.044272
1000002.088543
2500005.221359
50000010.44272
100000020.88543

What is the centipoise?

The centipoise (cP) is a CGS unit of dynamic (absolute) viscosity, equal to one hundredth of a poise. It is the most widely used practical viscosity unit in industry because water at about 20 °C has a viscosity of very nearly 1 cP.

Definition

One centipoise equals one hundredth of a poise, which in SI units is exactly one millipascal-second:

1 cP=0.001 Pa·s1\ \text{cP} = 0.001\ \text{Pa·s}

Since 1 P=0.1 Pa·s1\ \text{P} = 0.1\ \text{Pa·s} (the poise being defined as 1 g cm−1 s−11\ \text{g}\,\text{cm}^{-1}\,\text{s}^{-1}), the centipoise is 10−210⁻² of that, i.e. 1 cP=1 mPa·s1\ \text{cP} = 1\ \text{mPa·s} exactly. The unit is dimensionally mass per length per time.

Origin and History

The poise is named after the French physician and physiologist Jean Léonard Marie Poiseuille (1797–1869), who studied the flow of liquids (blood) through narrow tubes and formulated what became the Hagen–Poiseuille law. The centipoise arose as a convenient submultiple because water conveniently sits near 1 cP, making comparisons intuitive.

Law and Notable Facts

The centipoise is a CGS-derived unit and is not part of the SI, which prefers the pascal-second (Pa·s) or millipascal-second (mPa·s). Because 1 cP=1 mPa·s1\ \text{cP} = 1\ \text{mPa·s} exactly, conversion between the everyday industrial unit and the SI unit requires no arithmetic beyond a change of name — a coincidence that has helped the centipoise survive.

Real-World Examples and Conversions

Water at 20 °C is about 1.002 cP. Whole milk is roughly 3 cP, olive oil around 60–80 cP, and honey near 2,000–10,000 cP. SAE 30 motor oil at 20 °C is on the order of 200 cP. To convert, 500 cP=0.5 Pa·s=500 mPa·s500\ \text{cP} = 0.5\ \text{Pa·s} = 500\ \text{mPa·s}.

What is the pound-force-second per square foot?

The pound-force-second per square foot (lbf·s/ft²) is the unit of dynamic (absolute) viscosity in the English/US customary gravitational system. It is sometimes called the "slug per foot-second" because it is numerically identical to that combination.

Definition

One pound-force-second per square foot is the viscosity that produces a shear stress of one pound-force per square foot at a shear rate of one per second:

1 lbf·s/ft2=47.8803 Pa·s1\ \text{lbf·s/ft}^2 = 47.8803\ \text{Pa·s}

The exact value follows from the definitions 1 lbf=4.4482216152605 N1\ \text{lbf} = 4.4482216152605\ \text{N} and 1 ft=0.3048 m1\ \text{ft} = 0.3048\ \text{m}, giving 1 lbf·s/ft2=4.4482216152605/0.30482=47.880259 Pa·s1\ \text{lbf·s/ft}^2 = 4.4482216152605 / 0.3048² = 47.880259\ \text{Pa·s} exactly. It equals one reyn's cousin in ft units, and is identical to 1 slug ft−1 s−11\ \text{slug}\,\text{ft}^{-1}\,\text{s}^{-1}.

Origin and History

The unit belongs to the foot-pound-second (FPS) gravitational system used by English-speaking engineers, in which force (the pound-force) rather than mass is a base concept. It became standard in aeronautical and mechanical engineering texts in the United States during the 20th century, where fluid properties were often tabulated in customary units.

Law and Notable Facts

It is not an SI unit; the SI equivalent is the pascal-second. A closely related unit, the reyn (1 lbf·s/in²), is used in lubrication engineering and equals 6.89476×103 Pa·s6.89476\times10^{3}\ \text{Pa·s}, exactly 144 times the lbf·s/ft² because there are 144 square inches per square foot.

Real-World Examples and Conversions

Water at 20 °C, about 1.002 cP=0.001002 Pa·s1.002\ \text{cP} = 0.001002\ \text{Pa·s}, is roughly 2.09×10−5 lbf·s/ft22.09\times10^{-5}\ \text{lbf·s/ft}^2. Conversely, 1 lbf·s/ft2=47.8803 Pa·s=47,880.3 cP1\ \text{lbf·s/ft}^2 = 47.8803\ \text{Pa·s} = 47{,}880.3\ \text{cP}, a very viscous fluid comparable to thick syrup. Air at room temperature (≈1.8×10−5 Pa·s\approx 1.8\times10^{-5}\ \text{Pa·s}) is about 3.8×10−7 lbf·s/ft23.8\times10^{-7}\ \text{lbf·s/ft}^2.

Frequently Asked Questions

How many pound-force-seconds per square foot are in one centipoise?

One centipoise equals about 0.00002088543 lbf·s/ft², a very small number because the customary unit is enormous by comparison.

How many centipoises equal one lbf·s/ft²?

Roughly 47,880 centipoises make one pound-force-second per square foot, the reciprocal of the forward factor.

Where is the lbf·s/ft² unit used?

It appears in US mechanical and petroleum engineering — bearing lubrication, hydraulic, and pipe-flow calculations — where all quantities stay in the English engineering system.

What is 25 cP in lbf·s/ft²?

Multiply 25 by 0.00002088543 to get about 0.000522136 lbf·s/ft².

Why is the customary viscosity value so small in decimal form?

Because the pound-force-second per square foot is about 47,880 times bigger than a centipoise, ordinary fluids register as tiny fractions of it.

People also convert

cP to Pa-scP to mPa-scP to PcP to lb/(ft-s)

Complete centipoises conversion table

cP
UnitResult
pascal-seconds (Pa-s)0.001 Pa-s
millipascal-seconds (mPa-s)1 mPa-s
poises (P)0.01 P
pound-force-seconds per square foot (lbf-s/ft2)0.00002088543 lbf-s/ft2
pounds per foot-second (lb/(ft-s))0.000671969 lb/(ft-s)

Dynamic viscosity conversions