How many United Kingdoms fit in China?

38 United Kingdoms fit in China.

Really
38
As Mercator draws it
21

Mercator makes it look like only 21, fewer than the 38 that really fit. This time the container is the one nearer the equator, and so the one inflated less.

Why the two differ

Mercator draws United Kingdom 2.90 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
United Kingdom 248,884 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