Convert US gallons per day to Cubic kilometres per year
Convert US gallons per day (gpd) to Cubic kilometres per year (km³/yr) instantly and accurately.
Conversion Formula
km³/yr = gpd × 1.382621654e-9
About US gallons per day
The US gallon per day (gpd) equals 3.785411784×10⁻³/86400 ≈ 4.381×10⁻⁸ m³/s, the standard unit in US water-utility regulation and residential water-well pump sizing. The US national average residential water use is about 80-100 gpd per person; a reverse-osmosis membrane module is rated in gpd (50-100 gpd for domestic units). 1 US gpd ≈ 4.381×10⁻⁸ m³/s.
About Cubic kilometres per year
The cubic kilometre per year (km³/yr) equals 10⁹/(365.25×86400) ≈ 31.688 m³/s, the unit used in global hydrology, glaciology, and climate science for river basin runoff, ice-sheet mass balance, and groundwater storage change. Total global freshwater river runoff is ≈37 000 km³/yr; the Amazon alone contributes ≈6 600 km³/yr; the Greenland ice sheet loses ≈280 km³/yr to melt and calving. 1 km³/yr ≈ 31.69 m³/s.
Quick Reference Table
| US gallons per day (gpd) | Cubic kilometres per year (km³/yr) |
|---|---|
| 1 gpd | 1.383 × 10-9 km³/yr |
| 2 gpd | 2.765 × 10-9 km³/yr |
| 5 gpd | 6.913 × 10-9 km³/yr |
| 10 gpd | 1.383 × 10-8 km³/yr |
| 25 gpd | 3.457 × 10-8 km³/yr |
| 50 gpd | 6.913 × 10-8 km³/yr |
| 100 gpd | 1.383 × 10-7 km³/yr |