Gender ratios in select Allied countries after the Second World War 1950, by age

The Second World War severely altered the demographic composition of many countries, particularly in terms of gender ratios across certain age groups. For age groups below 14 years, there is little observable impact of the war on gender ratios, however, some countries see a drastic change across older generations, particularly in the Soviet Union. For men in their twenties (i.e. those in their late-teens or early-twenties when the war began), the ratio drops from 98 men per 100 women in the 15-19 age group, to 68 men per 100 women in the 25-29 group.

In addition to the Second World War, these figures are affected by trends in nature and other historical events. For example, women tend to have higher overall life expectancies than men, which typically sees gender ratios widen among older generations. The impact of the First World War is also most-observable in France's gender ratios for those aged in their fifties. Additionally, the gap in ratios remains high for the Soviet Union across older age groups due to the impact of the First World War and the famine of the early 1930s, however the figures for Russia itself are even lower as it was disproportionately affected by the Russian Revolution and famine of the 1920s.