How Much Water Is on Earth? One Ball, from One Liter to the Whole Planet | Scale Side by Side #03
Short answer
- From a one-liter bottle to a pool, Lake Biwa, Lake Baikal, and all the water on Earth — everything becomes a ball at the same scale.
- "All Earth's water" follows the USGS scope: oceans, frozen water, groundwater, atmospheric water, and more.
- Freshwater sits inside the total, and river-and-lake water inside that — the balls overlap, so their volumes are not added.
Video
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Explained
In the video
- 0:00What shape is one liter of water?
- 0:21Eight balls: what happens to the width?
- 0:41How does a whole pool become one ball?
- 0:52How small do the lakes get?
- 1:13How big is all the water on Earth?
- 1:42How does it look next to Earth?
- 2:00Can water balls be a ruler?
- 2:17What is inside all that water?
- 2:59What if only rivers and lakes remain?
- 3:31What does a real river look like?
- 3:50Back to the bottle: what did the scale show?
From 1 liter in a bottle to a swimming pool, Lake Biwa in Japan, Lake Baikal in Russia, and all Earth's water, we compare water volumes as balls at the same scale. Then we look at freshwater, which has a low salt content, and the water in rivers and lakes within it.
Water volumes and diameters
Diameter is the width through the center of a ball. Water volumes are given in liters (L), cubic meters (m³), or cubic kilometers (km³).
| Object or water amount | Water volume | Diameter shown in the video | Basis |
|---|---|---|---|
| Water in the bottle | 1 L | About 12 cm | Calculated from a set volume |
| 8 L of water | 8 L | Twice the 1 L ball's diameter | Calculated from a set volume |
| Water in the pool defined for this video | 2,500 m³ | About 17 m | Calculated from the defined dimensions |
| Water in Lake Biwa, Japan | About 27.5 km³ | About 3.7 km (estimate) | Calculated from a representative volume |
| Water in Lake Baikal, Russia | About 23,000 km³ | About 35 km (estimate) | Calculated from a representative volume |
| All Earth's water | About 1,386,000,000 km³ | About 1,380 km (estimate) | Calculated from an estimated volume |
| Earth, for size comparison | — | About 12,700 km | Calculated from the mean radius |
| All freshwater, including ice and groundwater | About 35,029,110 km³ | About 406 km (estimate) | Calculated by summing estimated volumes |
| Freshwater in rivers and lakes | About 93,120 km³ | About 56 km (estimate) | Calculated by summing estimated volumes |
The pool measures 50 m × 25 m inside, with a depth of 2 m throughout. Earth is modeled as a sphere with a mean radius of 6,371 km. The lakes use representative volumes, and the global estimates come from a 1993 source; these are not current measurements taken on the same day. “All Earth's water” follows the scope of the USGS water distribution table and excludes water bound in deep-Earth minerals.
What this episode shows
- Eight times the water volume makes a ball with twice the diameter. Width and water volume grow by different factors.
- A ball of all Earth's water has a diameter of about 1,380 km (estimate). Nine such balls lined up across Earth's diameter at the same scale leave a small gap.
- Most of Earth's water is in the oceans. Freshwater accounts for about 2.5% by volume (estimate), and freshwater in rivers and lakes is part of that. These water volumes overlap, so they must not be added together.
Shorts
Sources
Where the facts and numbers in the video and on this page come from.
- USGS Water Science School, “Where is Earth's Water?” (Global water distribution and the volumes of freshwater and freshwater in rivers and lakes. Original source: Igor Shiklomanov, “World fresh water resources”, in P. H. Gleick, ed., Water in Crisis (1993))usgs.gov/water-science-school/science/where-eart…
- USGS Water Science School, “How Much Water is There on Earth?” (Total water volume)usgs.gov/water-science-school/science/how-much-w…
- Shiga Prefecture, “Overview of Lake Biwa” (Lake Biwa's water volume, 27.5 km³)pref.shiga.lg.jp/de51/2878.html
- Water, Sinyukovich et al. (2024), 16, 560 (Section 2.1 gives Lake Baikal's water volume as about 23,000 km³)doi.org/10.3390/w16040560
- NASA, “Earth Fact Sheet” (Earth's mean radius, 6,371 km)nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html
- USGS Water Science School, “Freshwater (Lakes and Rivers) and the Water Cycle” (Definition of freshwater)usgs.gov/water-science-school/science/freshwater…
- Earth map: NASA Earth Observatory, Blue Marble Next Generation, July 2004.science.nasa.gov/earth/earth-observatory/blue-marble-nex…
- via USGS.water.usgs.gov/edu/gallery/watercyclekids/rivers.html
- Freshwater definition: USGSusgs.gov/water-science-school/science/freshwater…
Voice, music, art
- Music: “キューブスカイ” by かずち https://opentracks.com/bgm/detail/1364 / “宇宙の神秘” by 田中芳典 https://dova-s.jp/bgm/detail/12249 / “星屑サラウンド-1chorus-” by 龍崎一 https://dova-s.jp/bgm/detail/10010
- Voice: Kokoro. Sound effects: original synthesis and CC0 recordings from Freesound. 3D and calculations: Tamelabo.
