China’s population peaked at about 1.41 billion in 2021 and the UN projects it will fall to about 633 million by 2100 — while India is expected to keep growing until the early 2060s, when it could peak at about 1.7 billion.

Under earlier UN work, China’s projected 2100 population ranged from about 488 million to 1.153 billion, depending on whether you assumed low or high fertility, with the middle scenario in between. Pew Research Center found that “regardless of the precise timing of China’s population peak or the magnitude of its projected decline, there is near-universal consensus that the nation’s population is on a trajectory of decline.” The UN’s World Population Prospects 2024 puts it this way: “The population of India, which is expected to remain the world’s largest throughout the century, will likely decline by 12 per cent after reaching its peak in the early 2060s at about 1.7 billion.”