March Update on the 2026 Boston Marathon Cutoff Time Projection

For the past few months, I’ve been tracking the results of marathon finishers around the world in an attempt to project the cutoff time for the 2026 Boston Marathon. I put together a live tracker, and I published an early analysis in December and a follow-up in January.

The emerging picture suggested that the new qualifying times reduced the percentage of runners who met their BQ, but that an increasing number of runners are participating in marathons. This boost in finishers is, in many cases, offsetting the effects of the new qualifying times.

In the initial analysis, I anticipated a possible cutoff time in the three to five minute range, leaning towards five minutes. In the follow-up, I found that the additional data continued to point towards five minutes.

Since then, two months have gone by. This isn’t the busiest part of the year for marathons, but there have been quite a few races since late January.

So, how are things looking today?

What Has Happened Since the Last Update?

I published the last update in late January, after the Houston Marathon.

Since then, there have been 39 additional races with a collective 57,000 finishers added to the cutoff time tracker. The biggest of these were Los Angeles, Austin, Mesa, and Miami.

Finishers Have Continued to Increase

Across the board, the number of finishers at these races increased from 53,288 to 57,381 – an increase of 7.7%.

While Austin saw the greatest concentrated growth, there were increases across many of the races. Of the 39 races this year, 27 had more finishers than last year and only 12 had fewer. An additional two races – Skidaway Island and Hilton Head – were canceled this year.

Many of these races saw large gains – over 25% more finishers. Of the ones that shrank, nine of them did so by less than 10%.

In the long run, more runners means more qualifiers – and a tougher cutoff time.

But Qualifiers Trended Down

Although there were significantly more runners this year, the number of qualifiers was still down about 21% compared to this same set of races last year. That’s about what you’d expect from a normal race if the number of finishers remained about the same as last year – and the new qualifying times were applied.

So why did the number of qualifiers drop if the number of finishers increased?

There are likely two reasons:

1. Many of these races were hilly and tough. For example, neither Los Angeles nor Austin produce a lot of qualifiers. Tougher qualifying times are extra tough on a hilly course.
2. Many of the new finishers were young. They have the toughest qualifying times and qualify at the lowest rates – which compounds the impact of the tough courses.

This pushed the projection down slightly over the past two months, and if the number of qualifiers continues to be down ~20% compared to last year it would eventually push the projection below five minutes.

The Tokyo Marathon Saw a Decrease in Qualifiers

I haven’t incorporated the results from the Tokyo Marathon directly into the tracker, because the majority of the runners at Tokyo are Japanese – and very few Japanese runners actually apply to run Boston.

However, there is an increasing share of runners from the United States and other countries that do regularly run Boston. That number increased quite a bit from 2024 to 2025.

Compared to last year, the number of qualifiers from the top six countries represented at Boston – the United States, Canada, Great Britain, Mexico, Brazil, and China – dropped 16%. This is lower than the year to date difference (~7%) but not as low as the remainder of this period’s races (~20%).

In the scheme of things, Tokyo represents a wildcard that points to a slightly easier cutoff time – but it’s one of several wildcards to keep in mind. You can read a more thorough analysis of the Tokyo Marathon results here.

What Should You Look For in April?

Over the course of the next month, the picture will become increasingly clear. So far, we have results from about two thirds of all finishers throughout the qualifying period. April will bring another 20%. There are relatively few races remaining to be run between May and September.

If April yields significantly fewer qualifiers than last year (20-30% fewer), then it could push the cutoff time down below 5:00. If the number of qualifiers is in the range of 5-10% fewer than last year, it’ll lock in the current projection at around 5:30. And if there’s a bumper crop of additional qualifiers – we’re looking at 6+ minutes.

There are three big things to look for.

How Many Runners Will Requalify at Boston?

Three things point to this year’s Boston producing relatively more re-qualifiers than last year:

1. Last year was hot, and far fewer runners finished and requalified than in typical years. It’s still early for a confident forecast, but there doesn’t seem to be any evidence of a coming heat wave.
2. This year, they accepted 24,000 time qualifiers – 2,000 more than last year – and they issued an additional 2,000 bibs. So the field is larger, and those additional runners are fast.
3. Last year’s cutoff time was 6:51, so despite the tougher qualifying times most runners should be capable of beating their new qualifying times.

Combine those three things, and it’s possible that the 2025 Boston Marathon produces more qualifiers than 2024, in spite of the new qualifying times. And that would be bad news if you’re hoping for an easier cutoff time.

How Big Can London Go?

Last year, London was (briefly) the largest marathon in the world. Can it get bigger?

The numbers from the fall were so high in part because Berlin saw a huge surge in finishers. It’s unlikely that London will grow by that much, but organizers are expecting a field of over 56,000 runners.

How large that increase is and how old those new runners are will go a long way towards determining what happens with the number of qualifiers at London. It’s a big race, so if the numbers are down 10% to 15% compared to last year, that could have a strong impact on the projection.

What Happens In the Other Races?

And then there are the other 32 races, with 30,000 finishers. Will they continue to grow?

Unlike the races in the last two months, many of these races are fast and flat – or downhill. With easier courses, the impact of the new qualifying times won’t be quite as strong. So if the number of finishers is up 10% to 20% across the board, that would negate most of the potential decline in qualifiers.

Pay particular attention to the large downhill races – like REVEL Mt. Charleston and Mountains 2 Beach – as well as the large flat races – like Jersey City and Carmel. They produce a lot of qualifiers, and if any or all of them increase in size it’ll push things in the direction of a tougher cutoff time.

Check Back in Early May for A Follow Up

As of the end of March, the projection sat at 5:20.

Over the course of the next month, that could increase above 6:00, decrease below 5:00, or get locked in at around 5:30. Given how much is behind us, I don’t see a situation in which it moves lower than 4:00 or higher than 6:30.