J for boys, A for girls: the letters baby names start with

In 1880 one American boy in five had a name starting with J. Most of them were John, James or Joseph. Those three made up 82% of the J boys.

A hundred years later it was still more than one boy in five. But by 1980 John, James and Joseph were only 28% of the J boys. The rest were Jason, Joshua, Justin, Jeremy and Jonathan. The names had changed completely. The letter had not.

J has been the commonest first letter for American boys in every year we hold, from 1880 to 2017. Girls have had six different letters at the top in the same time. And in England and Wales today, J comes fifth.

How we counted

We took the first letter of every name, added up the babies, and worked out each letter's share of all the boys or all the girls born that year. The letter is the one on the birth record, so Aiden and Ayden both count as A.

For 1880 to 2008 we use the American top 1,000 names for each year. They covered 93% of babies in 1880 and 80% of boys and 67% of girls by 2008, so for those years the shares are of babies with a top-1,000 name. For 1990 to 2017 we also hold the full files, which list every name given to five or more babies. They say the same thing about which letter leads. For England and Wales we use the full 2025 file from the ONS.

One letter for 138 years

J has stayed between 14.8% and 22.4% of American boys in every one of those years. Its lowest was 1958 and its highest 1981. In between the J names were replaced, one generation at a time. In 1880 there were 58 J names in the top 1,000. In 2008 there were 117, and the biggest of them, Jacob, was only 8% of the J boys.

The closest call was 1953. J had 15.2% of boys, and R had 14.8%, thanks to Robert, Richard, Ronald and Roger. That year the top 1,000 covered 96% of boys. The other 4% we cannot see, and they would have needed a lot more R names than J names to change the order. So 1953 is a narrow J year, not a certain one.

Second place is where the change happened. W was second until 1914, on William and Walter. R took over in 1915 and held it until 1969. M had it from 1970 to 1990, on Michael, Matthew and Mark. A has been second since 1993, on Alexander, Anthony, Andrew and Aiden.

The most recent full American file we hold is 2017. J is still first, with 13.1% of boys, about one in eight. James, Jacob, Joseph, Jackson, Jayden, John, Jack and Julian were each given to more than 8,000 boys. A is second with 10.1%.

Girls changed letter every generation

M led from 1880 to 1940, and about a third of the M girls in 1890 were Mary. Then the letter changed with the names. J and M swapped the lead through the 1940s, on Judith, Judy and Joyce. D led from 1952 to 1960, on Debra, Deborah, Donna and Diane. L led from 1961 to 1966, on Lisa, Linda and Lori. Through the 1970s M, S, J and A traded places, with Jennifer and Jessica putting J in front most often.

A took the lead in 1979, by 12.6% to 12.2%, and has not let go in any year we hold since. That is a big turnaround. In 1949 A was the first letter of just 3.3% of girls, its lowest year on record. By 2007 it was 18.3%.

A has done what J did for the boys. It held on while its names turned over. In 1985 the A girls were led by Ashley and Amanda. In 2008 they were Ava, Abigail and Addison, and Ashley was down to 4% of them. In 2017, 18.0% of American girls had an A name, more than one in six.

In Britain, A leads for everyone

England and Wales has its own letter, and it is the same for boys and girls. In 2025, 13.3% of boys and 16.4% of girls had a name starting with A. Put together, that is 77,790 of 526,933 babies, about one in seven.

The British A boys are Arthur 3,211, Archie 2,465, Arlo 2,083, Alfie 1,955, Albie 1,702 and Adam 1,431. The girls are Amelia 2,153, Ava 1,611, Arabella 1,368, Aria 1,132, Aurora 1,030 and Ada 1,014.

J is fifth for British boys, with 6.9%. That is about half its American share in 2017. The biggest J name here is Jude, 2,153 boys and 14th. Then Jack 1,595, Jacob 1,258 and James 1,211. M is second, helped by Muhammad on its own with 5,957. The 2024 file says the same: A 13.5% of boys, J 7.3%.

Is America catching up?

Our American counts stop in 2017, but the rankings run to 2025. They count names, not babies, and they point one way. In 2015 the American boys' top 100 had 18 J names and 11 A names. In 2025 it had 13 J names and 14 A names.

Five J names left the top 100 in those ten years: Jaxon, Jordan, Jace, Jaxson and Jason. None came in. Six A names came in: Atlas, Axel, August, Adriel, Arthur and Archer. Three went out: Austin, Adam and Ayden.

The last time A names outnumbered J names in the American boys' top 100 was 1927. But J still led by babies that year, and every year, because John, James and Joseph were so big. A count of names is not a count of babies. So 2025 does not tell you A has taken over. It tells you J is a little less sure of itself than it has been for a long time. James is still sixth.

What it means for you

If you are in England and Wales and would like an initial your child shares with fewer classmates, J is half as common as A for a boy. For a girl it is rarer still: 1.8% of girls here had a J name in 2025, against 16.4% with an A.

In America it goes the other way for boys. J is still the letter you are most likely to share, and it has been in every year we have counts for.