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Volumetric Flux

gfdtoLMH

Convert US gallons per square foot per day (gfd) to litres per square metre per hour (LMH).

Factor1 gfd = 1.6977 LMH

Converter

gfd

Accepts numbers or expressions, e.g. 150 + 14.7

Result
50.931LMH

Rendered to 6 significant figures.

Formula

Formula
LMH = gfd × 1.6977

Multiply any value in US gallons per square foot per day by 1.6977 to obtain the value in litres per square metre per hour.

Worked example

Convert 30 gfd to LMH.

  1. 01Start with 30 gfd.
  2. 02Multiply by the conversion factor: 30 × 1.6977 = 50.931 LMH.
Result30 gfd = 50.931 LMH

Conversion table

gfdLMH
11.6977
23.3954
58.4885
1016.977
2033.954
5084.885
100169.77
200339.54
500848.85
10001697.7

Reference values rounded to 5 significant figures for display.

FAQ

What is the conversion factor from gfd to LMH?
1 gfd equals 1.6977 LMH. To convert, multiply the value in US gallons per square foot per day by 1.6977.
How do I convert 1 gfd to LMH?
1 gfd = 1.6977 LMH. For any value, multiply by 1.6977.
How do I convert LMH back to gfd?
Divide by the same factor — or equivalently, multiply by 0.5890322. So 1 LMH = 0.589032 gfd.
When would I need to convert US gallon per square foot per day to litre per square metre per hour?
Volumetric-flux conversions between gfd and LMH are routine in membrane filtration (RO, UF, MF, NF permeate flux), hydraulic loading specification, water-treatment design, hydrometallurgy and packed-bed column loading, and environmental engineering. LMH (L/m²/h) and gfd (gal/ft²/day) dominate membrane datasheets; m³/m²/h and m³/m²/day cover SI engineering ladders; m/day and cm/s appear as superficial velocity in hydromet and packed-bed work. Volumetric flux is the same physical quantity as superficial velocity (m³/m²/s ≡ m/s) but is kept distinct from the velocity and flow categories because the engineering intent is volumetric throughput per unit area, not bulk motion or total throughput.
Is the conversion exact?
The factor shown is precise to at least 7 significant figures. For most process-engineering work this is far better than instrument accuracy. For metrology or trade applications, refer to the relevant national standard (NIST, BIPM, ISO 80000).

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