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Volumetric Flux

gfdtom/day

Convert US gallons per square foot per day (gfd) to metres per day (volumetric flux) (m/day).

Factor1 gfd = 0.0407448 m/day

Converter

gfd

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

Result
4.07448m/day

Rendered to 6 significant figures.

Formula

Formula
m/day = gfd × 0.0407448

Multiply any value in US gallons per square foot per day by 0.0407448 to obtain the value in metres per day (volumetric flux).

Worked example

Convert 100 gfd to m/day.

  1. 01Start with 100 gfd.
  2. 02Multiply by the conversion factor: 100 × 0.0407448 = 4.07448 m/day.
Result100 gfd = 4.07448 m/day

Conversion table

gfdm/day
10.040745
20.08149
50.20372
100.40745
200.8149
502.0372
1004.0745
2008.149
50020.372
100040.745

Reference values rounded to 5 significant figures for display.

FAQ

What is the conversion factor from gfd to m/day?
1 gfd equals 0.0407448 m/day. To convert, multiply the value in US gallons per square foot per day by 0.0407448.
How do I convert 1 gfd to m/day?
1 gfd = 0.0407448 m/day. For any value, multiply by 0.0407448.
How do I convert m/day back to gfd?
Divide by the same factor — or equivalently, multiply by 24.54301. So 1 m/day = 24.543 gfd.
When would I need to convert US gallon per square foot per day to metre per day (volumetric flux)?
Volumetric-flux conversions between gfd and m/day 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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