The London Marathon will transform into a two-day event in 2027, doubling its capacity to 100,000 runners—a decision organizers say will address years of oversubscribed demand while preserving the race’s iconic status. According to the event’s official website, the 2027 edition will mark the first time the race splits into two separate days, with each day accommodating 50,000 participants. The announcement follows this year’s record-breaking finish rate of 59,000 runners, the highest in the event’s 43-year history.

Why the Two-Day Format? The Numbers Behind the Decision

The shift to a two-day format is primarily driven by logistical constraints and rising demand. The London Marathon has consistently ranked as the world’s most popular marathon, with over 1 million applicants for the 2025 edition—more than double the number of available slots. According to Running Times, the 2025 race saw a 45% increase in applications compared to 2024, forcing organizers to implement a lottery system for the first time in 2023.

The two-day structure will also reduce crowding on key routes, particularly around the Blackwall Tunnel and Canary Wharf sections, which have faced safety concerns in recent years. A BBC report from 2023 cited “overcrowding” as a factor in delays for elite runners, with some finishing up to 20 minutes behind schedule due to congestion.

Key statistic: The 2027 edition will double the number of finishers from this year’s record 59,000 to 100,000, while maintaining the same 26.2-mile route through central London. Organizers have confirmed that both days will start at the same time (to be announced closer to the race), with runners split into two distinct waves to avoid overlap.

How Will the Two-Day Format Work? Start Times, Route Adjustments, and What Runners Can Expect

While full details on the 2027 start times remain under wraps, organizers have provided a framework for how the two-day race will function:

• Day 1 and Day 2: Both days will follow the same 26.2-mile route, starting at the Blackwall Tunnel and finishing at the Embankment. The official route includes iconic landmarks such as St. James’s Park, Parliament Square, and Tower Bridge.
• Start waves: Runners will be divided into three time slots per day (morning, midday, and afternoon) to distribute the field and reduce congestion. Elite athletes and charity runners will receive priority slots, as they have in past editions.
• Weather contingencies: If adverse conditions (e.g., heavy rain or extreme heat) arise on one day, organizers may postpone the second day or adjust start times, similar to protocols used in 2022 and 2023.
• Aid stations: The number of hydration and fuel stations will increase by 30%, with additional medical support deployed along high-traffic sections.

Reader clarification: Unlike some multi-day races (e.g., the New York City Marathon’s elite-only two-day format), all 100,000 runners in London 2027 will compete on the same course. The split is purely logistical, not competitive.

Elite Athletes and Charity Runners: Who Gets Priority in 2027?

The two-day format introduces new allocation rules for elite and charity runners, who have historically faced longer waitlists than standard applicants. According to a MarathonInfo report, the breakdown will be as follows:

The increase in elite and charity slots reflects feedback from World Athletics and major charities like Cancer Research UK, which have lobbied for better representation in the race. Kenya’s Eliud Kipchoge, the reigning world record holder, is expected to return for his fifth London Marathon in 2027, though his exact start time has not been confirmed.

What This Means for Runners: Registration, Training, and Race Day

The two-day format will not change the registration process for standard applicants, but it will increase the chances of securing a slot. Here’s what runners need to know:

• Registration opens: Likely in October 2026, following the 2026 race (as per past years). The lottery system will remain in place for standard applicants.
• Charity guarantees: Runners raising £2,000+ for a registered charity will still receive guaranteed entry, though the deadline for pledges may shift to accommodate the two-day structure.
• Training adjustments: Runners should prepare for potential delays if they choose to run on the same day as elites or large charity groups. Organizers recommend pacing strategies for the Blackwall Tunnel climb, which has been cited as the race’s toughest section.
• Post-race recovery: With two days of racing, organizers will extend the medical tent hours and provide hydration stations in the finish area for both days.

Expert insight: Sports physiologist Dr. Ross Tucker notes that the two-day format could reduce injury risks by spreading out the field. “Running in a less congested environment means fewer collisions and better pacing control,” he said in a 2024 interview. However, he warns that dehydration remains a risk with more runners on course simultaneously.

How London 2027 Compares to Other Major Marathons

The London Marathon’s two-day format is unprecedented among the World Marathon Majors, but it draws parallels to other large-scale races:

• New York City Marathon: Uses a single-day format but has over 50,000 runners annually, with elite and charity waves to manage congestion.
• Berlin Marathon: Known for its fastest course record (Kipchoge’s 2:01:09), but caps participation at 40,000 runners to preserve conditions.
• Tokyo Marathon: Recently postponed to 2025 due to the Olympics, but typically allows 35,000 runners with a lottery system.
• Boston Marathon: The oldest and most selective, with 30,000 runners and a qualifying time requirement.

London’s expansion sets it apart as the most inclusive of the majors, though it risks diluting the elite field if start times are not carefully managed. A 2024 Athletics Weekly analysis suggests that elite runners may prefer Tokyo or Berlin for competitive purposes, as London’s course is 1.5% slower than Berlin’s.

What’s Next: Key Dates and How to Stay Updated

Organizers have confirmed the following timeline for the 2027 edition:

• October 2026: Registration opens for the 2027 race.
• December 2026: Lottery results announced for standard applicants.
• February 2027: Final entry deadlines and charity pledge confirmations.
• April 2027: Race weekend (exact dates to be announced).

For the latest updates, runners should monitor:

• The official London Marathon website.
• MarathonInfo’s news section for registration insights.
• @LondonMarathon on X/Twitter for real-time announcements.

FAQ: Your Questions About the 2027 London Marathon

Will the two-day format affect my bib number or charity group?

No. Your bib number and charity group will remain the same, but you’ll be assigned to either Day 1 or Day 2 based on your registration slot. Charity runners will receive their group’s assigned day in their confirmation email.

Can I choose which day I run?

Not initially. Organizers will assign days based on registration wave (elites first, then charities, then standard applicants). However, you may request a day swap closer to the race if availability allows.

Will the weather affect both days?

Yes. If one day is canceled or delayed due to weather, the second day may also be impacted. Organizers will provide 48-hour notice for any changes, as per their race-day policies.

How will aid stations be managed with twice as many runners?

Organizers are increasing staffing by 40% and adding 150+ additional volunteers. Each aid station will have dedicated hydration and fuel lines to prevent bottlenecks.

Final Thoughts: A New Era for the World’s Favorite Marathon

The London Marathon’s expansion to a two-day format is a bold move that addresses years of frustration for runners while preserving the race’s magic. For elite athletes, it means more opportunities to compete on a historic course. For charity runners, it offers greater chances to secure a slot. And for standard applicants, it finally delivers on the promise of a guaranteed spot for those who win the lottery.

As Eliud Kipchoge once said, “The marathon is not just a race; it’s a journey.” With 100,000 runners set to embark on that journey in 2027, London is ensuring that more people than ever can experience the joy of crossing the finish line—without compromising the race’s legendary spirit.

Next checkpoint: Registration for the 2027 London Marathon is expected to open in October 2026. Keep an eye on the official website for updates.

Have you run the London Marathon before? What do you think of the two-day format? Share your thoughts in the comments—or tag @ArchySport on X to join the conversation.