| Water source | Water volume | Percent of | ||
| (in cubic miles) | total water | |||
| Oceans | 317,000,000 | 97.24% | ||
| Icecaps, glaciers | 7,000,000 | 2.14% | ||
| Groundwater | 2,000,000 | 0.61% | ||
| Fresh-water lakes | 30,000 | 0.009% | ||
| Inland seas | 25,000 | 0.008% | ||
| Soil moisture | 16,000 | 0.005% | ||
| Atmosphere | 3,100 | 0.001% | ||
| Rivers | 300 | 0.0001% | ||
| Total water volume | 326,000,000 | 100% |
Source: USGS, [1984] The Hydrologic Cycle (Pamphlet)