Convert L/(dm²·min) to CFM per Square Foot

Formula

ft³/(ft²·min) = L/(dm²·min) × 0.3280839895013

or ft³/(ft²·min) = L/(dm²·min) ÷ 3.048

Derivation from SI units:

• 1 L/(dm²·min) = 10⁻³ m³ ÷ (10⁻² m² × 60 s) = 1/600 m/s ≈ 1.667 mm/s
• 1 ft³/(ft²·min) = 0.3048³ m³ ÷ (0.3048² m² × 60 s) = 0.00508 m/s = 1 ft/min
• 1 L/(dm²·min) = 0.001666666666667 m/s ÷ 0.00508 m/s per ft³/(ft²·min) = 0.3280839895013 ft³/(ft²·min)

Both units are defined exactly, so the factor is exact. Liter per Square Decimeter per Minute definition: liter per square decimeter per minute; CFM per Square Foot definition: cubic foot per square foot per minute.

Worked examples

1. A reading of 20 L/(dm²·min) converts to 6.56167979 ft³/(ft²·min).
   20 L/(dm²·min) × 0.3280839895 = 6.56167979 ft³/(ft²·min)
2. A value of 200 L/(dm²·min) is 65.6167979 ft³/(ft²·min).
   200 L/(dm²·min) × 0.3280839895 = 65.6167979 ft³/(ft²·min)

Where it's used

Liters per Square Decimeter per Minute are used for older European fabric permeability reports (e.g. DIN-based), while cubic feet per square foot per minute appear in ASTM D737 fabric air permeability (inch-pound reporting). Both measure face velocity and air permeability (volumetric flow per unit area), so the conversion is a fixed factor.

Liter per Square Decimeter per Minute 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 8 (litre, minute).
• ASTM D737 Standard Test Method for Air Permeability of Textile Fabrics, ASTM International , inch-pound results in ft³/min/ft².
• 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, "foot per minute".

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