centistokes (cSt) to square feet per second (ft2/s) conversion

1 cSt = 0.00001076391 ft2/sft2/s → cSt
Formula
1 cSt = 0.00001076391 ft2/s

Understanding centistokes to square feet per second Conversion

The centistokes (cSt) is the practical CGS unit of kinematic viscosity — the ratio of dynamic viscosity to density — and water at 20 °C is about 1 cSt. The square foot per second (ft²/s) is the US customary unit of kinematic viscosity and is enormously larger: one ft²/s equals about 92,903 cSt. Converting centistokes to square feet per second is important when oil-analysis or lubricant data reported in cSt must be entered into American fluid-dynamics calculations that use the foot-second system.

Conversion Formula

1 cSt=0.00001076391 ft2/s1\ \text{cSt} = 0.00001076391\ \text{ft2/s}

To convert centistokes to square feet per second, multiply by this factor:

ft2/s=cSt×0.00001076391\text{ft2/s} = \text{cSt} \times 0.00001076391

Step-by-Step Example

Convert 25 centistokes to square feet per second.

ft2/s=25×0.00001076391=0.000269098 ft2/s\text{ft2/s} = 25 \times 0.00001076391 = 0.000269098\ \text{ft2/s}

How to Convert centistokes to square feet per second

Convert a metric kinematic-viscosity reading into US customary units in one step.

  1. Take the centistokes value: Start with the viscosity in cSt, for example 25 cSt.
  2. Multiply by 0.00001076391: This is the number of ft²/s in one centistokes.
  3. Calculate: 25×0.00001076391=0.00026909825 \times 0.00001076391 = 0.000269098.
  4. Report the result: 25 centistokes equals about 0.000269098 square feet per second.

centistokes to square feet per second conversion table

centistokes (cSt)square feet per second (ft2/s)
00
10.00001076391
20.00002152782
30.00003229173
40.00004305564
50.00005381955
60.00006458346
70.00007534737
80.00008611128
90.00009687519
100.0001076391
150.0001614587
200.0002152782
250.0002690978
300.0003229173
400.0004305564
500.0005381955
600.0006458346
700.0007534737
800.0008611128
900.0009687519
1000.001076391
1500.001614587
2000.002152782
2500.002690978
3000.003229173
4000.004305564
5000.005381955
6000.006458346
7000.007534737
8000.008611128
9000.009687519
10000.01076391
20000.02152782
30000.03229173
40000.04305564
50000.05381955
100000.1076391
250000.2690978
500000.5381955
1000001.076391
2500002.690978
5000005.381955
100000010.76391

What is the centistokes?

The centistokes is a unit of kinematic viscosity, describing how readily a fluid flows under the influence of gravity by combining its dynamic viscosity and density. It is widely used in the petroleum, lubricant, and food industries because most everyday fluids fall in a convenient range when measured in centistokes.

Definition

The centistokes is one hundredth of a stokes, the CGS unit of kinematic viscosity. One stokes equals one square centimetre per second, so one centistokes equals one square millimetre per second.

1 cSt=1.00000×10−6 m2/s1\ \text{cSt} = 1.00000 \times 10⁻⁶\ \text{m}^2/\text{s}

Equivalently, 1 cSt=1 mm2/s=10−2 St1\ \text{cSt} = 1\ \text{mm}^2/\text{s} = 10⁻²\ \text{St}. Kinematic viscosity is the ratio of dynamic viscosity to density: ν=μ/ρ\nu = \mu / \rho.

Origin and History

The stokes was named after the Irish physicist Sir George Gabriel Stokes (1819–1903), whose work on fluid flow led to Stokes' law and the Navier–Stokes equations. The name was adopted within the centimetre–gram–second (CGS) system of units, and the centistokes emerged as a practical subunit because water and many light oils have viscosities near 1 cSt.

Law and Notable Facts

The stokes and centistokes are not SI units, but they remain accepted for use and are ubiquitous in industry standards such as ASTM D445 and ISO 3104. Conveniently, pure water at about 20 °C has a kinematic viscosity of very nearly 1 centistokes, making it a natural reference point.

Real-World Examples and Conversions

  • Water at 20 °C: about 1.004 cSt (1.004×10−6 m2/s1.004 \times 10⁻⁶\ \text{m}^2/\text{s}).
  • SAE 30 motor oil at 40 °C: roughly 100 cSt.
  • Automotive gear oils are graded partly by their viscosity in centistokes at 100 °C.
  • 100 cSt=1 St=1.00000×10−4 m2/s100\ \text{cSt} = 1\ \text{St} = 1.00000 \times 10⁻⁴\ \text{m}^2/\text{s}.

What is the square foot per second?

The square foot per second is an imperial and US customary unit of kinematic viscosity, expressing how quickly momentum diffuses through a fluid relative to its density. It appears in older engineering references and in fields where imperial units persist, such as parts of the oil and gas industry.

Definition

One square foot per second is the kinematic viscosity of a fluid in which an area of one square foot's worth of momentum diffusion occurs each second. Because one foot equals exactly 0.3048 metre, the conversion follows directly from squaring that length.

1 ft2/s=0.0929030 m2/s1\ \text{ft}^2/\text{s} = 0.0929030\ \text{m}^2/\text{s}

Exactly, 1 ft2/s=(0.3048)2 m2/s=0.09290304 m2/s=92903.04 cSt1\ \text{ft}^2/\text{s} = (0.3048)^2\ \text{m}^2/\text{s} = 0.09290304\ \text{m}^2/\text{s} = 92903.04\ \text{cSt}.

Origin and History

The unit derives from the imperial foot, a length whose modern definition was internationally standardized in 1959 as exactly 0.3048 metre. Kinematic viscosity expressed in ft²/s follows the same dimensional pattern as its SI counterpart (m²/s), simply substituting the foot for the metre.

Law and Notable Facts

The square foot per second is a coherent unit within the foot–pound–second system rather than an SI unit. It is a comparatively large unit: even highly viscous industrial fluids rarely exceed a small fraction of 1 ft²/s, so most practical values are much less than one.

Real-World Examples and Conversions

  • Water at 20 °C (~1.004 cSt) is only about 1.08×10−5 ft2/s1.08 \times 10⁻⁵\ \text{ft}^2/\text{s}.
  • A heavy oil at 100 cSt equals about 1.076×10−3 ft2/s1.076 \times 10⁻³\ \text{ft}^2/\text{s}.
  • 1 ft2/s=0.09290304 m2/s1\ \text{ft}^2/\text{s} = 0.09290304\ \text{m}^2/\text{s}.
  • 1 m2/s≈10.7639 ft2/s1\ \text{m}^2/\text{s} \approx 10.7639\ \text{ft}^2/\text{s}.

Frequently Asked Questions

How many square feet per second are in one centistokes?

One centistokes equals about 0.00001076391 ft²/s, a tiny fraction because the customary unit is very large.

How many centistokes are in one square foot per second?

About 92,903 centistokes make up one ft²/s, the reciprocal of the forward factor.

What does kinematic viscosity measure?

It is dynamic viscosity divided by density, describing how readily a fluid flows under gravity; unlike dynamic viscosity it has units of area per time.

What is 25 cSt in square feet per second?

Multiply 25 by 0.00001076391 to get about 0.000269098 ft²/s.

Where would I need this conversion?

In oil and lubricant analysis, where viscosity grades are quoted in centistokes but downstream US-customary flow or lubrication models expect ft²/s.

People also convert

cSt to m2/scSt to mm2/scSt to St

Complete centistokes conversion table

cSt
UnitResult
square metres per second (m2/s)0.000001 m2/s
square millimetres per second (mm2/s)1 mm2/s
stokes (St)0.01 St
square feet per second (ft2/s)0.00001076391 ft2/s

Kinematic viscosity conversions