Recently, the BAA released the field of entrants into the 2025 Boston Marathon.
On the website, you can look up an individual runner or search for filtered groups of runners. The data includes their bib number, wave, corral, name, age, city, state, and country. For some reason, the current list does not include gender.
Last year, this data was released as a csv file which made it easy to download and analyze. This year, you can only view the data on the website. However, I was able to work out a way to page through the results and collect them.
Overall, there are 32,080 runners on this year’s entry list. That’s an increase over last year’s 29,685. There’s a problem on BAA’s website for the 2023 Boston Marathon entry list, but based on the number of bibs issued the total number of entrants was somewhere between 30,000 and 32,000.
I wrote up a thorough analysis of the entry list on Medium, and if you’re not a Medium subscriber you can request a special link to read the article here.
In the meantime, I’ll share a brief synopsis of the data, along with some visuals, below.
What Countries Do International Entrants Come From?
About one third of the entrants into the Boston Marathon come from outside of the United States.
The visual below breaks out the numbers for the top ten countries (including the United States). The remainder of the entrants are combined into the “Other” category.
The donut on the left shows the data for last year’s field and the donut on the right shows the data for this year’s field.
The general breakdown is very similar, although a slightly higher portion of the field is coming from overseas this year.
The top countries from which athletes come remains more or less the same, although the order gets shuffled up a little bit once you get outside the top five.
After the United States, the next four most common countries are Canada, Great Britain, Mexico, and Brazil. The general proportion of runners from each country remains about the same, and the absolute number for three of the four increased. Brazil is the only one with a slight decrease in the absolute number.
Note that this data is based on the runner’s country of residence. There is a separate field tracking a runner’s country of citizenship, and some portion of the runners labeled USA are foreign citizens who permanently live in the United States.
What States Do American Runners Come From?
Next, let’s take a quick look at which states the American portion of the field come from.
This visual is structured similar to the previous one. It breaks the ~20,000 American runners down by state, enumerating the top ten states and combining the rest of the field into “Other.”
Unsurprisingly, Massachusetts is number one. It’s home to the marathon, so it’s likely more popular there than anywhere else. There are also a decent number of invitational bibs given out to sponsors and locals that bolsters their numbers.
The remaining states track somewhat with the general population of each state. The most populous states in the country – California, Texas, Florida – are all on the list.
Local states (New York, Pennsylvania, New Jersey) do rank a little higher than they otherwise would.
Colorado is the biggest outlier on the list. It’s far down on the list of the largest states in the country (~6 million people), and it’s the smallest state in the top ten. But it ranks above larger states like New Jersey and Ohio.
The overall proportions have stayed pretty much the same between this year and last year.
What’s the Age Breakdown of This Year’s Entrants?
Finally, let’s take a quick look at how old the runners are at Boston.
Recently, I did an analysis of the finishers from the 2024 Boston Marathon and found that they were much older than the general population of marathon runners in the United States. In particular, the 45-49 age group is heavily overrepresented.
This visual shows the percentage of the field that is in each age group, from under 20 to 80 and over. For each group, the bar on the right signifies the number for this year and the bar on the left signifies the number for next year.
The general distribution is similar from last year to this year, but there are some small shifts within that distribution.
The younger age groups – 20 to 34 – have all grown in size. The middle age groups – 35-54 – have all shrunk slightly.
On the one hand, the stricter qualifying times advantage older runners. So with last year’s cutoff, you’d expect a shift to the right. But there’s also been a huge influx of younger runners into the sport, so that may be compensating for the cutoff.
This trend may find itself reversed next year, when the next cutoff times take effect and runners under 60 find themselves at a relative disadvantage.
What Are Your Thoughts?
Did any of that data surprise you – or maybe spark some additional questions? Leave a comment below.
If you haven’t, you should read the full analysis on Medium. It includes a few additional visuals, and I offer some insights into the differences between American and international runners. I took a look at DNF’s by country from last year’s race to lay the groundwork for an analysis of whether or not international runners in 2025 decided to drop out.
Again, if you’re not a subscriber, you can request a special link to read the Medium article here.
I’ll be using this list to perform some additional analysis, including identifying attempting to identify which runners qualified for Boston through a downhill race and understanding which races are more or less likely to result in applicants.
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