One in how many

In 1880 one American boy in twelve was called John. One girl in fourteen was Mary. Those were the most popular names in the country, and popular meant something. Walk into any school and you would find a John in every row.

In 2017, the most recent full American file we hold, the most popular boys' name was Liam. One boy in 98. Emma was the most popular girls' name, at one in 87. In England and Wales last year Olivia was number one for girls, and it went to one girl in 106.

Same word, popular. Eight times less of it. When somebody tells you a name is too popular, this article is what the number actually looks like.

How many names it takes to cover half the babies

The cleanest way to measure this is not the top name but the whole list. Start at number one and keep adding names until you have covered half of all the boys born that year. In 1880 that took 16 names. In 2008, the last year of the long series, it took 128. For girls it went from 43 names to 311.

Read the shape before the numbers. For seventy years the lines barely move. The girls' line actually comes down between 1910 and 1947, and the boys' line drops from 37 names in 1910 to 23 in 1946. Then the girls' line turns upwards in the late 1950s and never stops. The boys' line waits until about 1985 and then does the same, only steeper.

The whole spread, from a few dozen shared names to a few hundred, happened inside one lifetime.

The 1950s were the last time everyone shared

Here is the same thing decade by decade, with the number one name each time and what fraction of babies got it.

Two things stand out. The first is how long nothing changed. Mary was the most popular girls' name in America for 76 of the 129 years in the series, every year from 1880 to 1946 and again from 1953 to 1961. John held the boys' title for 44 years straight, from 1880 to 1923, and Michael managed 44 years too, in two spells either side of a single year of David. The number one name used to be a fixture, not a fashion.

The second is that 1950 was not the start of the spread. It was the peak of the opposite. The top 100 boys' names covered 76% of all boys born in 1950, more than in 1880. It took 24 names to cover half of them, and in 1946 it took 23, the fewest in any year since 1889. Mid-century America was not where names started to scatter. It was the most crowded the maternity ward has been since the records began.

Put it another way. In 1950 there were 21 boys' names and 19 girls' names that each had a bigger share of babies than the number one name of 2008 had. Being number one in 2008 would have got you about 20th in 1950.

The biggest years any name has had

The same story in raw babies. These are the highest single-year counts in the American records for the names that have been number one.

Linda in 1947 is the record, 99,686 girls, and we wrote about what happened to it in the first article on this site. Five names have had a year above 88,000. The best year any current name has managed is Liam's 18,728 in 2017. The number one name of today gets a fifth of what the number one of 1947 got.

It is the top that shrank, not the middle

You might expect the whole list to have thinned out. It has not. The hundredth boys' name in 1880 was Calvin, given to one boy in 883. In 1950 it was Clifford, one in 618. In 2008 it was Eli, one in 484. The hundredth name is as common as it has ever been. Slightly more so.

So the change is not that parents spread out across the whole list. It is that the top twenty or so names, which used to swallow a third of all babies, stopped doing that. The top ten covered 41% of boys in 1880 and 33% in 1950. In 2008 it covered 9%. Popular names did not get rarer. The very popular ones did.

Britain today

The English and Welsh file for 2025 tells the same story from the other end. It takes 177 names to cover half of the girls in it and 116 to cover half of the boys. The top 100 girls' names cover 39% of girls, and the top 100 boys' names 47% of boys. That is a little more bunched than America on both sides: in the 2017 American file the top 100 covered 42% of boys and 34% of girls.

The one place Britain is an outlier is the boys' number one. Muhammad went to one boy in 46 last year, more than twice the share Liam had in America. Why that one name bucks a hundred-year trend is a question about how the name is counted as much as how often it is chosen, and it deserves an article to itself.

What it means for you

If you are avoiding a name because it is popular, know what you are avoiding. In the 2017 American file the tenth boys' name, Jacob, went to one boy in 140, and the tenth girls' name, Abigail, to one girl in 162. In 1950 the tenth names were Gary at one in 54 and Kathleen at one in 68. A top ten name today is what a top fifty name was then.

So the popular list is worth reading with that in mind. Number one is not what it was. Nothing is. Pick the one you like.