Back in 1846, a British woman could reasonably expect to be married before her 25th birthday, most likely to a man not much older: The average age of nuptials for a single woman was 24.7 and for a single man, 25.7.
But marriage is no longer the province of twentysomethings in Western countries.
Since the 1970s there’s been a clear trend in the UK for rising age at first marriage—which excludes people who were previously married and have divorced or lost a spouse—according to data from the UK’s Office for National Statistics (which has data back to the mid-19th century.) The average age for single men to marry passed 30 in 1999. For women, it was 2010:
The data to 2016, the most recent available, were released in March 2019. The ONS noted that in heterosexual unions, the age at first marriage in 2016 for men was 33.4 and for women was 31.5, part of a trend of rising age since the 1970s. For marriages between same-sex couples the average age was higher: 40.8 for men and 37.4 for women. (Same-sex marriage data goes back to 2014, when it became legal in the UK.)
The UK numbers reflect a growing trend in wealthy Western countries towards getting hitched later. In the rest of Europe, mean age at first marriage is higher then 30 in Germany, France, Spain, and many more of the regions most-developed economies. The US, meanwhile, has seen its median age at first marriage (which the United States Census Bureau estimates, rather than releasing a mean), creep up from around 20 for women in the 1970s to 27.8 in 2018. Men’s age at first marriage that year was 29.8.
Shifting social norms around cohabitation are a factor. “The major move towards living together before marriage may well help to explain many of the relationship trends we see today,” writes Nick Stripe, head of life events (that includes births, deaths, and baby names) at the ONS, in a blog accompanying the data. Almost 90% of couples marrying in 2016 had lived together beforehand.
Many people are also waiting longer to have kids. In 2017, for the first time, more UK women became pregnant over the age of 30 than in their 20s. Not all pregnancies lead to childbirth—in fact, the average British women’s age at the birth of their first child in 2017 was 28.8. But that number has been rising steadily since the 1970s, when the average dipped below 24.