Convert kinematic viscosity units — m²/s, Stokes, centistokes, ft²/s and more.
| Unit | Name | Value |
|---|---|---|
| m²/s | Square Meter/Second | 0.092903 |
| cm²/s | Square Centimeter/Second | 929.03 |
| St | Stokes | 929.03 |
| cSt | Centistokes | 92903 |
| in²/s | Square Inch/Second | 143.99994 |
Formula: Stokes = ft²/s × 929
Multiply any ft²/s value by 929 to get Stokes.
Reverse: ft²/s = Stokes × 0.001076
Water reference (20°C): 1.0807e-5 ft²/s = 0.01004 St
Values at ~20°C unless noted. Factor: 1 ft²/s = 929 St
| ft²/s (ft²/s) | Stokes (St) | Fluid |
|---|---|---|
| 1.615e-07 ft²/s | 0.00015 St | Air (20°C) |
| 5.382e-06 ft²/s | 0.005 St | Petrol (gasoline) |
| 1.081e-05 ft²/s | 0.01004 St | Water (20°C) |
| 1.615e-05 ft²/s | 0.015 St | Ethanol |
| 3.229e-05 ft²/s | 0.03 St | Diesel fuel |
| 0.0003767 ft²/s | 0.35 St | SAE 10W motor oil |
| 0.0009042 ft²/s | 0.84 St | Olive oil |
| 0.001076 ft²/s | 1 St | SAE 30 motor oil |
| 0.001938 ft²/s | 1.8 St | SAE 90 gear oil |
| 0.01518 ft²/s | 14.1 St | Glycerin (20°C) |
| 0.05382 ft²/s | 50 St | Honey |
| 0.08611 ft²/s | 80 St | Molasses |
| 0.5382 ft²/s | 500 St | Tomato ketchup |
| 2.691 ft²/s | 2500 St | Peanut butter |
| 1.076e+16 ft²/s | 1.000e+19 St | Glass (room temp) |
1 ft²/s = 929 St.
Water at 20°C = 1 cSt = 0.01 St = 10⁻⁶ m²/s. Use as reference.
Multiply result by 0.001076 to recover the original ft²/s value.
Specifies lubricant viscosity grades in cSt at 40°C and 100°C per ISO VG and SAE standards.
Uses kinematic viscosity in cSt for pipeline flow calculations, pump sizing, and heat exchanger design.
Measures crude oil and refined product viscosity in cSt for pipeline transport and refinery design.
Selects hydraulic fluids based on kinematic viscosity in cSt for pump compatibility and system efficiency.
Characterizes food product viscosity (honey, sauces, oils) in cSt for process design and quality control.
Uses ft²/s or cSt for atmospheric kinematic viscosity in Reynolds number calculations for aircraft design.
Square foot per second (ft²/s) is the Imperial kinematic viscosity unit, equal to 0.0929 m²/s = 929 St. It is used in US aerospace and some civil engineering contexts where the foot-pound-second system is standard.
ft²/s appears in some US military fluid specifications and older aerospace engineering handbooks. Water at 20°C ≈ 1.075×10⁻⁵ ft²/s. Air ≈ 1.57×10⁻⁴ ft²/s. The large scaling factor (1 ft²/s = 929 St) makes it impractical for most engineering use.
Interesting fact: The kinematic viscosity of the atmosphere at different altitudes is important for aircraft design — Reynolds number calculations use kinematic viscosity. The US Standard Atmosphere tables list kinematic viscosity in ft²/s at each altitude for use in US aerospace engineering.
The Stokes (St) is the CGS unit of kinematic viscosity, equal to exactly 1 cm²/s = 10⁻⁴ m²/s. It was named after Sir George Gabriel Stokes by the British Association for the Advancement of Science in 1882.
The Stokes is used in petroleum engineering and some industrial viscometer specifications. Water at 20°C = 0.01 St = 1 cSt. Engine oils range from 50–200 cSt (0.5–2 St) at 40°C. Pourable molasses is about 5–10 St (500–1,000 cSt).
Interesting fact: George Stokes was also the first to explain fluorescence (Stokes shift), derive the Navier-Stokes equations of fluid motion, and develop the theory of diffraction. His work in fluid mechanics in the 1840s–1850s remains fundamental to modern engineering.
Kinematic viscosity (ν = μ/ρ) measures how a fluid flows under gravity. The cSt is dominant in industry; m²/s is the SI unit; St and cm²/s are the CGS equivalents. Key anchor: water at 20°C ≈ 1 cSt = 10⁻⁶ m²/s = 0.01 St.
Exact factor: 1 ft²/s = 929 St. Reverse: 1 St = 0.001076 ft²/s.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.