Convert Feet per Day to Gallons per Day per Square Foot
1 foot per day (ft/day) = 7.480519481 US gallons per day per square foot (gpd/ft²). 1 gpd/ft² = 0.1336805556 ft/day. Example: 15 ft/day = 15 × 7.480519481 = 112.2077922 gpd/ft².
Also searched as feet per day to gpd/ft2, feet per day in gpd/ft2, feet per day into US gallons per day per square foot, ft/day to gpd/ft2, ft/day in US gallons per day per square foot, ft/day into US gallon per day per square foot, foot per day to US gallon per day per square foot, ft/day to US gallons per day per square foot converter and how many US gallons per day per square foot in a foot per day.
1 ft/day = 7.480519481 gpd/ft²
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk foot per day to gpd/ft² converter to paste a column from Excel.
How to Convert Foot per Day to Gallon per Day per Square Foot
- 1 ft/day = 7.480519481 gpd/ft²
- 1 gpd/ft² = 0.1336805556 ft/day
- Example: convert 15 ft/day to gpd/ft²: 15 ft/day = 15 × 7.480519481 gpd/ft² = 112.2077922 gpd/ft²
Formula
gpd/ft² = ft/day × 7.480519480519
Derivation from SI units:
- 1 ft/day = 0.3048/86,400 m/s.
- 1 gpd/ft² = 0.003785411784 m³ ÷ 86,400 s ÷ 0.09290304 m².
- 1 ft/day = 0.000003527777777778 m/s ÷ 4.715952932099 × 10⁻⁷ m/s per gpd/ft² = 7.480519480519 gpd/ft²
Both units are defined exactly, so the factor is exact. Foot per Day definition: foot per day; Gallon per Day per Square Foot definition: US gallon per day per square foot.
Worked examples
- A reading of 3 ft/day converts to 22.44155844 gpd/ft².
3 ft/day × 7.480519481 = 22.44155844 gpd/ft² - A value of 50 ft/day is 374.025974 gpd/ft².
50 ft/day × 7.480519481 = 374.025974 gpd/ft²
Foot per Day to Gallon per Day per Square Foot conversion table
| Feet per Day (ft/day) | Gallons per Day per Square Foot (gpd/ft²) |
|---|---|
| 0.01 ft/day | 0.07480519481 gpd/ft² |
| 0.1 ft/day | 0.7480519481 gpd/ft² |
| 1 ft/day | 7.480519481 gpd/ft² |
| 3 ft/day | 22.44155844 gpd/ft² |
| 10 ft/day | 74.80519481 gpd/ft² |
| 30 ft/day | 224.4155844 gpd/ft² |
| 50 ft/day | 374.025974 gpd/ft² |
| 100 ft/day | 748.0519481 gpd/ft² |
| 300 ft/day | 2244.155844 gpd/ft² |
| 1000 ft/day | 7480.519481 gpd/ft² |
Where it's used
Feet per Day are used for USGS aquifer reports, while US gallons per day per square foot appear in older USGS and well-driller reports. Both measure hydraulic conductivity (coefficient of permeability k), so the conversion is a fixed factor.
Foot per Day to other hydraulic conductivity units
| Conversion | 1 ft/day equals |
|---|---|
| foot per day to gpd/ft² | 7.480519481 gpd/ft² |
| foot per day to metre per second | 0.000003527777778 m/s |
| foot per day to centimetre per second | 0.0003527777778 cm/s |
| foot per day to metre per day | 0.3048 m/day |
| foot per day to centimetre per hour | 1.27 cm/h |
| foot per day to millimetre per hour | 12.7 mm/h |
| foot per day to inch per hour | 0.5 in/h |
Frequently asked questions
How many US gallons per day per square foot are in 1 foot per day?
1 ft/day = 7.480519481 gpd/ft².
How do I convert feet per day to US gallons per day per square foot?
Multiply the value in ft/day by 7.480519481. For example, 15 ft/day × 7.480519481 = 112.2077922 gpd/ft².
Is the ft/day to gpd/ft² conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- 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".
- 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, "gallon (U.S.)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Feet per Day to Gallons per Day per Square Foot. Retrieved October 29, 2026, from https://scientificconverters.com/hydraulic-conductivity/feet-per-day-to-gallons-per-day-per-square-foot/
IEEE
Scientific Converters, "Convert Feet per Day to Gallons per Day per Square Foot," scientificconverters.com. Accessed: Oct. 29, 2026. [Online]. Available: https://scientificconverters.com/hydraulic-conductivity/feet-per-day-to-gallons-per-day-per-square-foot/