Africa will be last to peak.
Peak at around 9.3 Billion souls will happen around 2070 according this forecast.
However, this article predicts that earth can only support 9-10 Billion people food-wise.
Globally, the fertility rate is falling to the “replacement level” — 2.1 children per woman, the rate at which children replace their parents (and make up for those who die young). If the global fertility rate does indeed reach replacement level by the end of the century, then the human population will stabilize between 9 billion and 10 billion. As far as Earth’s capacity is concerned, we’ll have gone about as far as we can go, but no farther.
but I suspect with solar power getting cheaper, battery technology better, and ever lower birthrates. The earth can support much more than anyone ever imagined. and there will be abundance of freshwater, food, and energy….If we all cooperate and don’t kill each other first.