Convert Square Millimeters per Second to Stokes

Formula

St = mm²/s ÷ 100

Derivation from SI units:

• 1 mm²/s = 10⁻⁶ m²/s = 1 cSt
• 1 St = 1 cm²/s = 10⁻⁴ m²/s
• 1 mm²/s = 0.000001 m²/s ÷ 0.0001 m²/s per St = 0.01 St

Both units are defined exactly, so the factor is exact. Square Millimeter per Second definition: square millimeter per second; Stokes definition: stokes.

Worked examples

1. A reading of 32 mm²/s converts to 0.32 St.
   32 mm²/s × 0.01 = 0.32 St
2. A value of 220 mm²/s is 2.2 St.
   220 mm²/s × 0.01 = 2.2 St

Where it's used

Square Millimeters per Second are used for lubricant ISO VG grades (VG 32, 46, 68 …), while stokes appear in older physics and fluid-mechanics references. Both measure kinematic viscosity (dynamic viscosity divided by density), so the conversion is a fixed factor.

Square Millimeter per Second to other kinematic viscosity units

Frequently asked questions

Sources

• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 2 with SI prefix milli.
• Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "stokes (St)".

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.