How many base pairs are in human DNA?
How many base pairs are in human DNA?
about 3.1 billion per copy — 6.2 billion in most cells
Stretched out, the DNA in one cell is about two metres long. Across 30 trillion cells that is roughly 60 billion kilometres — about ten times the distance to Pluto.
The human genome is about 3.1 billion base pairs long, and because most cells carry two copies — one from each parent — a typical nucleus holds around 6.2 billion. Only about 1.5% of it codes for protein, across roughly 20,000 genes, which is fewer genes than a water flea has. The genome was declared complete in 2003 but about 8% remained unread until 2022, when long-read sequencing finally resolved the repetitive centromeric regions.
How the figure is arrived at
Sequencing: chop the genome into overlapping fragments, read each one, and reassemble by overlap. Short-read sequencing could not resolve long repeated stretches, which is why the last 8% waited two decades for reads long enough to span them.
How confident it is
- Low estimate
- 3,000,000,000
- High estimate
- 3,200,000,000
- Spread
- 1.1× between the bounds
Other the human body counts
- How many bones are in the human body? 206 in an adult — about 300 at birth
- How many cells are in the human body? about 30 trillion human cells, plus 38 trillion bacteria
- How many neurons are in the human brain? about 86 billion
- How many muscles are in the human body? about 600 skeletal muscles
- How many hairs are on your head? about 100,000
- How many taste buds do you have? about 2,000 to 8,000
- How long are all your blood vessels? commonly quoted as 100,000 km — but probably closer to 20,000
Common questions
- How many base pairs are in human DNA?
- about 3.1 billion per copy — 6.2 billion in most cells
- How is that estimated?
- Sequencing: chop the genome into overlapping fragments, read each one, and reassemble by overlap. Short-read sequencing could not resolve long repeated stretches, which is why the last 8% waited two decades for reads long enough to span them.
Related pages
- How many bones are in the human body? 206 in an adult — about 300 at birth
- How many cells are in the human body? about 30 trillion human cells, plus 38 trillion bacteria
- How many neurons are in the human brain? about 86 billion
- How many muscles are in the human body? about 600 skeletal muscles
- How many hairs are on your head? about 100,000
- How many taste buds do you have? about 2,000 to 8,000
- How long are all your blood vessels? commonly quoted as 100,000 km — but probably closer to 20,000
- How many people are there in the world? Living things and the natural world
- 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 grains of sand are there on Earth? Living things and the natural world
- How many ants are there in the world? Living things and the natural world
- How many trees are there in the world? Living things and the natural world
Sources
- Typical range compiled from manufacturer specifications — At One Place