Convert Meters per Second to Millimeters per Second

Formula

mm/s = m/s × 1000

Derivation from SI units:

• 1 m/s = 1 m ÷ 1 s (equivalently 1 m³/s of flow per 1 m² of area)
• 1 mm/s = 0.001 m ÷ 1 s = 1 L/(m²·s)

Both units are defined exactly, so the factor is exact. Meter per Second definition: meter per second; Millimeter per Second definition: millimeter per second.

Worked examples

1. A reading of 0.4 m/s converts to 400 mm/s.
   0.4 m/s × 1000 = 400 mm/s
2. A value of 2 m/s is 2000 mm/s.
   2 m/s × 1000 = 2000 mm/s

Where it's used

Meters per Second are used for filter face velocity (ISO 16890 full-size filters ≈ 2.7 m/s), while millimeters per second appear in air permeability of fabrics, nonwovens and papers (ISO 9237, EN ISO 9237). Both measure face velocity and air permeability (volumetric flow per unit area), so the conversion is a fixed factor.

Meter per Second to other face velocity & air permeability units

Frequently asked questions

Sources

• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 2, coherent derived units.
• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 2 with SI prefix milli.
• ISO 9237:1995 Textiles — Determination of the permeability of fabrics to air, International Organization for Standardization , results expressed in mm/s.

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