Convert Stokes to Square millimetres per second

Convert Stokes (St) to Square millimetres per second (mm²/s) instantly and accurately.

Stokes (St)
Square millimetres per second (mm²/s)

Conversion Formula

mm²/s = St × 100

About Stokes

The stoke (St) equals 1 cm²/s = 10⁻⁴ m²/s, the CGS unit of kinematic viscosity named after Sir George Gabriel Stokes. Its hundredth part, the centistoke, is now dominant, but the stoke still appears in older fluid-mechanics texts and archival API and ASTM data. Water at 20 °C ≈ 0.01004 St; air at 20 °C ≈ 0.1516 St. 1 St = 100 cSt = 10⁻⁴ m²/s.

About Square millimetres per second

The square millimetre per second (mm²/s) equals 10⁻⁶ m²/s, numerically identical to 1 centistoke (cSt). It is the preferred SI-consistent expression: ISO 3104, DIN 51562, and ASTM viscosity standards all use mm²/s interchangeably with cSt. Water at 20 °C ≈ 1.004 mm²/s; SAE 10W-30 at 100 °C: 9.3-12.5 mm²/s. 1 mm²/s = 1 cSt.

Quick Reference Table

Stokes (St)Square millimetres per second (mm²/s)
1 St100 mm²/s
2 St200 mm²/s
5 St500 mm²/s
10 St1000 mm²/s
25 St2500 mm²/s
50 St5000 mm²/s
100 St10000 mm²/s

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