Biology
How much DNA is in one human cell?
All 3 billion base pairs of DNA in a human cell, about 2 metres of it, fit into a nucleus roughly 6 micrometres across.
Source: Alberts et al., Molecular Biology of the Cell (6th ed., 2014) (2014).
Context
About 2 metres, if you took the 3 billion base pairs and stretched them into a single line. It fits inside a nucleus roughly 6 micrometres across.
It fits because it is wound around proteins and then coiled, and coiled again. Molecular Biology of the Cell, the standard textbook, lays out the packaging.
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