Convert Square Feet per Second to mm²/s

Formula

mm²/s = ft²/s × 92903.04

Derivation from SI units:

• 1 ft²/s = 0.09290304 m²/s (exact)
• 1 mm²/s = 10⁻⁶ m²/s = 1 cSt
• 1 ft²/s = 0.09290304 m²/s ÷ 0.000001 m²/s per mm²/s = 92903.04 mm²/s

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

Worked examples

1. A reading of 0.00005 ft²/s converts to 4.645152 mm²/s.
   0.00005 ft²/s × 92903.04 = 4.645152 mm²/s
2. A value of 0.0005 ft²/s is 46.45152 mm²/s.
   0.0005 ft²/s × 92903.04 = 46.45152 mm²/s

Where it's used

Square Feet per Second are used for US hydraulics and pipe-flow calculations, while square millimeters per second appear in lubricant ISO VG grades (VG 32, 46, 68 …). Both measure kinematic viscosity (dynamic viscosity divided by density), so the conversion is a fixed factor.

Square Foot per Second to other kinematic viscosity units

Frequently asked questions

Sources

• 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, "square foot per second (ft²/s)".
• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 2 with SI prefix milli.

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