這個討論非常有意思。下麵是CIA所作的2010年世界主要國家人口中位數年齡的估計。非洲國家的中位數年齡都很低，這裏沒有列出來。這從全世界人口中位數年齡（28.4）可看出來。
| Country | Median age |
| Japan | 44.6 |
| Italy | 44.3 |
| Germany | 43.7 |
| Austria | 42.6 |
| Finland | 42.3 |
| Greece | 42.2 |
| Belgium | 42.0 |
| Sweden | 41.7 |
| Bulgaria | 41.6 |
| Spain | 41.5 |
| Switzerland | 41.3 |
| Netherlands | 40.8 |
| Canada | 40.7 |
| Denmark | 40.7 |
| United Kingdom | 40.5 |
| Czech Republic | 40.4 |
| France | 39.7 |
| Hungary | 39.7 |
| Norway | 39.7 |
| Portugal | 39.7 |
| Ukraine | 39.7 |
| Singapore | 39.6 |
| Russia | 38.5 |
| Poland | 38.2 |
| Korea, South | 37.9 |
| Australia | 37.5 |
| New Zealand | 36.8 |
| United States | 36.8 |
| China | 35.2 |
| Korea, North | 33.9 |
| Thailand | 33.7 |
| Chile | 31.7 |
| Argentina | 30.3 |
| Tunisia | 29.7 |
| Brazil | 28.9 |
| World | 28.4 |
| Turkey | 28.1 |
| Indonesia | 27.9 |
| Iran | 27.6 |
| Vietnam | 27.4 |
| Mexico | 26.7 |
| India | 25.9 |
| Egypt | 24.0 |
| Niger | 15.2 |
