How tall is an eastern koala?

There is no such species or sub-species as the "eastern koala".

Koalas vary in height according to whether they are from the north or the southern regions of Australia.

Koalas in northern parts of Australia are smaller, with males growing to a height (or body length) of 74 cm and females growing to 72 cm. Southern koalas are larger. The males can grow to 82 cm and females can grow to 73 cm.