My Spring 2025 Update for the 2026 Boston Marathon Cutoff Time Prediction
As I mentioned in December, I was waiting for the results of the 2025 Boston and London marathons to update my prediction for the 2026 Boston Marathon cutoff time.
Boston and London are two of the heavy hitter qualifiers that drive the number of applications to the following Boston marathon. They are usually cited by the B.A.A. as among the top 5 qualifiers.
Once again, I have tabulated the results from the BIB50 qualifiers (the top 50 North American qualifiers plus Berlin and London) that have completed to date. Here is a brief summary that compares the current qualification period to the previous qualification period (i.e. the one that fed last week’s Boston Marathon.)
Let’s review the data in terms of the trends observed so far this qualification period, which I highlighted in my November and December predictions.
1. The interest in marathon running continues to soar.
The number of finishers to date of the BIB50 qualifiers this qualifying period rose to 392,567 an increase of 11% over the qualifying period for this year’s race.
2. The increase in marathon finishers was very nearly outpacing the effect of the tightening of the 2026 Boston Marathon qualification standards.
Look at the numbers highlighted in yellow in the above chart.
To date there have been 54,205 BQ’s among the BIB50 qualifiers as evaluated against the new standards imposed by the B.A.A. (5 minutes tighter for all runners younger than 60 years old, no change for runners 60 years old and older.) This compares to 56,859 BQ’s for the same time period the previous year evaluated using the older standards, a drop of only 4.67%.
That 11% increase in finishers mentioned previously offsets some of the standards change. To date the number of BQ’s generated is down by less than 5%. That is a larger dropoff than what I reported in November, which was 2.98%. Yet it is still a small change in the face of a tightening of the qualification standards.
The number of BQ’s drives the number of applicants which drives the cutoff time.
For some perspective, the BQ’s generated and the BQ rate for the current qualification period as evaluated against the old standards is also shown. The BQ rate hasn’t changed that much, 16.80% this year compared to 16.08% last year.
This means that, on the whole, runners have not gotten appreciably faster year over year when evaluated against the old qualification standards.
3. For any given qualifier, race day weather is enormously influential.
In the 2023 race, the weather in Boston was nearly ideal for runners. As a result, the BQ rate was an amazing 52%. Historically, the BQ rate for Boston is in the mid 30% range, which is where it was for the hotter 2024 race (~38%).
Last week, the ideal weather returned to Boston and the BQ rate was 52% again when evaluated against the old qualification standards. Adjusting for the new standards, the BQ rate was 45%. This is still quite high compared to historical results.
London went in the other direction. It was hot this year along the Thames. The number of BQ’s dropped considerably but by a smaller amount than the increase in Boston BQ’s.
On a side note, the Carmel Marathon was cancelled this year due to the presence of thunderstorms in the area.
Using these data and estimates for the remainng BIB50 races taking into account historical and current finisher rate trends, I am predicting between 34,513 and 35,540 applicants for the 2026 Boston Marathon. This compares to 36,393 applicants for last week’s race.
I assume the same number of accepted applicants in 2026 as was the case for last week’s race, hence 24,069. Using the same algorithm as I used in November and December, a review of the BIB50 data to date suggests a 2026 cutoff time in the range of 5:49 to 6:23 (6:06 +/- 0:17) compared to from the 4:18 to 6:36 (5:27 +/- 1:09) reported in December.
Of course, if fewer applicants are accepted the cutoff time will increase. Remember that for the 2024 race only 22,019 applicants were accepted. A change of 1800 accepted applicants changes the cutoff time by about a minute.
The tighter range of the current prediction reflects that only a few of the BIB50 races remain and none of them have anywhere near the impact of Chicago, Boston, London, Berlin, or CIM (last year’s top 5 qualifiers.)
There are 15 remaining qualifiers in my BIB50 collection for the current qualification period. Perhaps fewer if some of them don’t make it into the double-dip weekend as was the case with Big Cottonwood last year. Downhill races are prominent among these remaining qualifiers.
Given the likely trend in 2026 cutoff time, I am anticipating keen interest in the upcoming downhills.
