When will Tanzania overtake Türkiye in population?

Turkey is about 19.8 million ahead today, but its fertility has dropped to 1.6 births per woman and the UN projects its population to peak around 2047 and then fall. Tanzania has a median age of 17 and 4.5 births per woman, so it keeps growing right through the century. The result is a crossover in the mid 2030s and a gap that then widens fast: 262 million for Tanzania against 65.7 million for Turkey in 2100.

Tanzania is projected to overtake Türkiye in total population around 2035. At the crossover, both countries sit at roughly 90.5 million people. Today Türkiye 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. Tanzania is on course to more than double over the century, moving from about 67.6 million in 2024 toward 262 million by 2100. Türkiye, by contrast, is projected to fall sharply, going from roughly 87.4 million to 65.7 million over the same period. Differences in fertility and age structure (Tanzania's median age near 17 versus Türkiye's near 33 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 2035 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, Tanzania rising relative to Türkiye, is robust across the plausible range of outcomes.