How many drops of water are there in the ocean?
How many drops of water are there in the ocean?
about 27 septillion
There are about a hundred times more drops in the ocean than there are stars in the observable universe.
The oceans hold about 1.33 billion cubic kilometres of water, a figure that is known to within a few percent from satellite altimetry and sea-floor bathymetry. A "drop" is not a physical constant, but pharmacy convention fixes it at 20 drops per millilitre, or 0.05 mL. Multiply the two and you get roughly 2.7 × 10^25 drops. Unlike most entries on this page the uncertainty is small, because the ocean's volume is genuinely well measured — the wobble is all in what counts as a drop.
How the figure is arrived at
1.33 billion km³ × 10^15 mL per km³ = 1.33 × 10^24 mL. At 20 drops per mL that is 2.66 × 10^25 drops. If you prefer a "drop" of 0.1 mL — closer to what falls off a tap — halve the answer.
How confident it is
- Low estimate
- 26,000,000,000,000,000,000,000,000
- High estimate
- 28,000,000,000,000,000,000,000,000
- Spread
- 1.1× between the bounds
Other living things and the natural world counts
- How many people are there in the world? about 8.2 billion
- How many grains of sand are there on Earth? roughly 7.5 quintillion on the world's beaches
- How many ants are there in the world? about 20 quadrillion
- How many trees are there in the world? about 3 trillion
- How many insects are there? about 10 quintillion
- How many species are there? about 8.7 million
- How many people have ever lived? about 117 billion
- How many fish are there in the sea? somewhere between 3 trillion and 100 trillion — nobody knows
- How many species are endangered? more than 45,000 assessed as threatened
- How many bees are there in the world? roughly 2 trillion managed honey bees
- How many birds are there in the world? about 50 billion wild birds
- How many bacteria are there on Earth? about 5 nonillion
- How many earthquakes are there each year? about 20,000 located a year — around 55 a day
- How many chickens are there in the world? about 26 billion alive at any moment
Common questions
- How many drops of water are there in the ocean?
- about 27 septillion
- How is that estimated?
- 1.33 billion km³ × 10^15 mL per km³ = 1.33 × 10^24 mL. At 20 drops per mL that is 2.66 × 10^25 drops. If you prefer a "drop" of 0.1 mL — closer to what falls off a tap — halve the answer.
Related pages
- How many people are there in the world? about 8.2 billion
- How many grains of sand are there on Earth? roughly 7.5 quintillion on the world's beaches
- How many ants are there in the world? about 20 quadrillion
- How many trees are there in the world? about 3 trillion
- How many insects are there? about 10 quintillion
- How many species are there? about 8.7 million
- How many people have ever lived? about 117 billion
- How many fish are there in the sea? somewhere between 3 trillion and 100 trillion — nobody knows
- How many stars are there in the universe? Space and the universe
- How many countries are there in the world? Things people built
- How many bones are in the human body? The human body
- How many stars are there in the Milky Way? Space and the universe
- How many atoms are there in the universe? Space and the universe
- How many galaxies are there? Space and the universe
Sources
- Calculated on this page — At One Place