How many people live per square kilometre in Manila?

How to get close to this number

Reason from what the built form allows. A square kilometre is a hundred hectares; at European apartment-block density you fit somewhere around ten to fifteen thousand people, and the densest cities on Earth push that several times higher through smaller dwellings, more occupants per room and almost no space given to anything else.

The comparisons in the explanation are the calibration: this is roughly three times denser than one of Europe's densest cities and eight times denser than a typical large European capital. Density figures mean nothing in isolation, and anchoring against cities you have walked around is the only way to feel what the number describes.

Administrative boundaries distort these figures more than almost any other urban statistic. A city measured tightly around its historic core reads as extraordinarily dense, while the same urban area measured across its full metropolitan sprawl reads as ordinary. This figure describes a specific, small administrative city rather than the whole conurbation around it.