Volumetric Flux
gfdtoL/m²/day
Convert US gallons per square foot per day (gfd) to litres per square metre per day (L/m²/day).
Factor1 gfd = 40.7448 L/m²/day
Converter
gfd
Accepts numbers or expressions, e.g. 150 + 14.7
Result
L/m²/day
Rendered to 6 significant figures.
Formula
Formula
L/m²/day = gfd × 40.7448
Multiply any value in US gallons per square foot per day by 40.7448 to obtain the value in litres per square metre per day.
Worked example
Convert 30 gfd to L/m²/day.
- 01Start with 30 gfd.
- 02Multiply by the conversion factor: 30 × 40.7448 = 1222.34 L/m²/day.
Result30 gfd = 1222.34 L/m²/day
Conversion table
| gfd | L/m²/day |
|---|---|
| 1 | 40.745 |
| 2 | 81.49 |
| 5 | 203.72 |
| 10 | 407.45 |
| 20 | 814.9 |
| 50 | 2037.2 |
| 100 | 4074.5 |
| 200 | 8149 |
| 500 | 20372 |
| 1000 | 40745 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from gfd to L/m²/day?
1 gfd equals 40.7448 L/m²/day. To convert, multiply the value in US gallons per square foot per day by 40.7448.
How do I convert 1 gfd to L/m²/day?
1 gfd = 40.7448 L/m²/day. For any value, multiply by 40.7448.
How do I convert L/m²/day back to gfd?
Divide by the same factor — or equivalently, multiply by 0.02454301. So 1 L/m²/day = 0.024543 gfd.
When would I need to convert US gallon per square foot per day to litre per square metre per day?
Volumetric-flux conversions between gfd and L/m²/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).
Related conversions
- L/m²/day → gfdlitre per square metre per day → US gallon per square foot per day
- m/s → gfdmetre per second (volumetric flux) → US gallon per square foot per day
- gfd → m/sUS gallon per square foot per day → metre per second (volumetric flux)
- m³/m²/s → gfdcubic metre per square metre per second → US gallon per square foot per day
- gfd → m³/m²/sUS gallon per square foot per day → cubic metre per square metre per second
- m³/m²/h → gfdcubic metre per square metre per hour → US gallon per square foot per day