Convert kinematic viscosity units — m²/s, Stokes, centistokes, ft²/s and more.
| Unit | Name | Value |
|---|---|---|
| cm²/s | Square Centimeter/Second | 10000 |
| St | Stokes | 10000 |
| cSt | Centistokes | 1000000 |
| ft²/s | Square Foot/Second | 10.763915 |
| in²/s | Square Inch/Second | 1550.0031 |
Formula: in²/s = m²/s × 1550
Multiply any m²/s value by 1550 to get in²/s.
Reverse: m²/s = in²/s × 0.0006452
Water reference (20°C): 1.0040e-6 m²/s = 0.001556 in²/s
Values at ~20°C unless noted. Factor: 1 m²/s = 1550 in²/s
| m²/s (m²/s) | in²/s (in²/s) | Fluid |
|---|---|---|
| 1.500e-08 m²/s | 2.325e-05 in²/s | Air (20°C) |
| 5.000e-07 m²/s | 0.000775 in²/s | Petrol (gasoline) |
| 1.004e-06 m²/s | 0.001556 in²/s | Water (20°C) |
| 1.500e-06 m²/s | 0.002325 in²/s | Ethanol |
| 3.000e-06 m²/s | 0.00465 in²/s | Diesel fuel |
| 3.500e-05 m²/s | 0.05425 in²/s | SAE 10W motor oil |
| 8.400e-05 m²/s | 0.1302 in²/s | Olive oil |
| 1.000e-04 m²/s | 0.155 in²/s | SAE 30 motor oil |
| 0.00018 m²/s | 0.279 in²/s | SAE 90 gear oil |
| 0.00141 m²/s | 2.186 in²/s | Glycerin (20°C) |
| 0.005 m²/s | 7.75 in²/s | Honey |
| 0.008 m²/s | 12.4 in²/s | Molasses |
| 0.05 m²/s | 77.5 in²/s | Tomato ketchup |
| 0.25 m²/s | 387.5 in²/s | Peanut butter |
| 1.000e+15 m²/s | 1.550e+18 in²/s | Glass (room temp) |
1 m²/s = 1550 in²/s.
Water at 20°C = 1 cSt = 0.01 St = 10⁻⁶ m²/s. Use as reference.
Multiply result by 0.0006452 to recover the original m²/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 meter per second (m²/s) is the SI unit of kinematic viscosity, defined as dynamic viscosity divided by fluid density. It measures how easily a fluid flows under gravity relative to its own inertia. The unit was formalized with SI in 1960.
m²/s values are very small for most fluids: water at 20°C ≈ 1×10⁻⁶ m²/s; air ≈ 1.5×10⁻⁵ m²/s; SAE 30 motor oil ≈ 1×10⁻⁴ m²/s. The large exponents make m²/s impractical for everyday use, which is why cSt and St are more common.
Interesting fact: Kinematic viscosity is the ratio ν = μ/ρ (dynamic viscosity ÷ density). A very viscous but dense fluid can have lower kinematic viscosity than a less viscous but very light fluid — which is why kinematic viscosity (not dynamic) governs flow by gravity.
Square inch per second (in²/s) is occasionally used in US precision engineering and hydraulic system specifications where inch-based units are standard. One in²/s = 6.4516×10⁻⁴ m²/s = 6.4516 St.
In²/s appears in some US hydraulic fluid specifications and industrial machinery manuals. A typical hydraulic fluid at 40°C might be specified as 0.04 in²/s (40 cSt). It is rarely used in modern practice compared to cSt.
Interesting fact: Hydraulic systems in US aircraft were historically specified using in²/s for fluid viscosity, alongside psi for pressure and gpm for flow — a fully inch-pound unit system that required separate conversion when integrating with metric components.
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 m²/s = 1550 in²/s. Reverse: 1 in²/s = 0.0006452 m²/s.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.