When will DR Congo overtake Mexico in population?

Mexico's fertility has fallen below the replacement level, to 1.9 births per woman, and the UN projects its population to peak around 2059, with net emigration trimming growth further. DR Congo, with a median age of 16 and 6.0 births per woman, is on a very different path. In 1990 Mexico had more than twice DR Congo's population; the projection has DR Congo ahead by the early 2030s and at 429 million against Mexico's 131 million by 2100.

DR Congo is projected to overtake Mexico in total population around 2033. At the crossover, both countries sit at roughly 140 million people. Today Mexico is still larger, but the trend lines are converging and the order is set to flip within a generation.

The reason is a tale of two trajectories. DR Congo is on course to more than double over the century, moving from about 108 million in 2024 toward 429 million by 2100. Mexico, by contrast, is projected to stay broadly flat, going from roughly 130 million to 131 million over the same period. Differences in fertility and age structure (DR Congo's median age near 16 versus Mexico's near 29 today) explain much of the divergence.

Crossovers like this one are how the global population ranking is quietly rewritten. As faster-growing populations climb the table and slower-growing or shrinking ones slip down, the list of the world's largest countries in 2100 will look markedly different from today's. The 2033 crossing is one of the clearer signals of that shift.

As with all long-range projections, the exact year carries uncertainty. Under the UN's high and low fertility scenarios the crossover could arrive earlier or later, and the figures here follow the medium variant. Still, the direction of travel, DR Congo rising relative to Mexico, is robust across the plausible range of outcomes.