How many Japans fit in China?

23 Japans fit in China.

Really
23
As Mercator draws it
23

Mercator very nearly tells the truth here - the two sit at similar latitudes, so the inflations cancel.

Why the two differ

Mercator draws Japan 1.61 times its true area and China 1.59 times. The count is the ratio of the two, so what moves it is not the inflation itself but the ratio between the two inflations. Whichever sits closer to a pole is blown up more.

Ruler
Japan 404,385 km²
Container
China 9,407,792 km²

On an equal-area projection

Under Equal Earth or Gall-Peters the two figures are identical - for every pair on this site. An equal-area projection draws in proportion to true area, so the count you can see is the count there is. That is a definition, not a coincidence.

Open on Equal Earth