It is literally impossible to find a common denominator when it comes to marriage age around the world. Factors such as customs and economic issues play an important role in deciding the average age at marriage in different countries. In some areas, religion is also a major component when deciding marriage age. The differences can be staggering.

In the US, for example, the average age at marriage varies according to social status, family traditions, and even geographical situation. Generally speaking, people in big cities tend to marry later and wait longer to have children, normally well into their 30s. People growing up in rural communities will probably get married for the first time in their early twenties. In developed countries, the average age at marriage has also been pushed back because many couples now choose to live together for years before even considering marriage. In the 1950s, when sharing a home before marriage wasn't the standard, people got married younger.

In countries such as India and Pakistan, where it is tradition that parents arrange weddings, the average age at marriage is 17, with many brides getting married as soon as they turn 15. This is the case also in many African countries, where economic factors force parents to marry off their daughters at an early age. Nigeria has some of the lowest averages in Africa, with most men getting married around 23 and most women at 17.

The average age at marriage peaks higher in Scandinavian countries such as Denmark, where the number is 30.2 for women and 32.5 for men. Sweden, Finland, and Norway are closely behind. In continental Europe, the average age at marriage is lower in the Eastern countries, where the numbers are barely 23 years of age for women in Poland and 26 for men in Romania.

China and Japan have joined European countries in their high averages, which are around 30 years old for both men and women. This is especially true of the major metropolitan zones, but rural areas are quickly catching up to the trend. It's important to note that, in many countries, the average age at marriage is closely related to the number of divorces that occur every year. Young couples have almost three times the chance of ending up divorced than people getting married after 27 years old.