London Marathon 2027 : the Double, the course km by km and travel

Both days of the 2027 Double run the same road, which the organiser describes as “from Greenwich to Westminster”. It is a point-to-point course that finishes 36.3 m lower than it starts, and it spends 35.4 m of that drop inside the first 10 km. After that London is flat, crowded and twisting, and its hard part is not a hill but the Docklands, where the towers interfere with a watch. The kilometres below follow the course as it ran in 2026, from the start line on Charlton Way in Blackheath; no change for 2027 had been published.

Km 0 to 4.8: three starts, downhill

London has grown so much that it now uses three start lines, around Greenwich Park and Blackheath. The road starts at about 41 m above sea level, peaks at 44.5 m near km 2.2 in Charlton, and then falls: to 16 m at Mile 3 (km 4.8). The organiser calls Miles 1 to 3 “wide roads and net downhill”, and its pacer’s advice is not to pick up too much speed on the descent around Mile 3. The slope is gentle, under 2% over any kilometre, which is exactly why it is easy to run too fast.

Runners from all three start lines meet for the first time just before Mile 3, in Woolwich, and the route turns west there.

Km 4.8 to 10.2: west to the Cutty Sark

Woolwich Church Street, Woolwich Road and Trafalgar Road carry the course west through Charlton towards Greenwich, and the road keeps falling, to about 5 m by km 6.4 and about 3 m by km 8. After km 8 it never again rises above 11.2 m. Romney Road brings it into Greenwich, and between Miles 6 and 7 the course loops round the Cutty Sark on Greenwich Church Street, at about km 10.1.

Km 10.2 to 19.5: Deptford, Rotherhithe and Bermondsey

Creek Road and Evelyn Street lead through Deptford, then Lower Road, Surrey Quays Road, Redriff Road and Salter Road take the course round Rotherhithe, close to the river. Brunel Road joins Jamaica Road in Bermondsey at about km 17.8, and Jamaica Road runs on towards Tower Bridge.

Km 19.5 to 23.6: Tower Bridge and halfway

The course crosses Tower Bridge northbound, from about km 19.7 to km 20.0. The organiser’s own words for it: “Soak up the energy of the roaring crowds and let the wall of noise push you across the River Thames towards the halfway point.” East Smithfield leads onto The Highway at about km 20.7, and halfway falls on The Highway, heading east. Narrow Street takes the course through Limehouse to Westferry Road at about km 23.6.

Km 23.6 to 32: the Isle of Dogs and Canary Wharf

Westferry Road runs down the west side of the Isle of Dogs, and the course’s lowest point, 1.8 m, comes at about km 25.9. Manchester Road and East Ferry Road lead through Mudchute, then Marsh Wall, Bank Street and North Colonnade bring it through Canary Wharf, past One Canada Square between about km 29.3 and km 31.1. Poplar High Street and West India Dock Road lead out again.

This is the stretch the organiser’s pacer warns about, Miles 15 to 20: “The tall buildings and narrow streets in Canary Wharf, and the Westferry Underpass, can cause GPS issues. Use Mile Markers for reliable distance references.” The crowd support is good, there are a few twists and turns, and “it can get windy as the tall buildings and narrow streets act as tunnels”. Trust the mile markers.

Km 32 to 38.6: Rainbow Row, The Highway and the Tower

Commercial Road and Butcher Row bring the course back onto The Highway at about km 33.9, now heading west. Just past Mile 21 comes Rainbow Row, a 250-metre stretch in Limehouse where, in the organiser’s words, everyone unites to celebrate the LGBTQIA+ community, and the pacer expects big crowds along The Highway around Miles 21 and 22. East Smithfield and Tower Hill take the course past the Tower, and Lower and Upper Thames Street run through the City to Victoria Embankment at about km 38.6.

Km 38.6 to the finish: the Embankment, Parliament and The Mall

The pacer calls the road from Tower Hill to Victoria Embankment “a favourable section for your tired legs”, and the Embankment runs flat beside the river for over 2 km. With about a mile to go the route turns right by Westminster Bridge into Parliament Square, at the foot of the Elizabeth Tower at about km 40.9. Great George Street leads to Birdcage Walk, which the pacer says “becomes very emotional with one kilometre (0.6 miles) to go”. The last turn, in front of Buckingham Palace, puts runners on The Mall and the finish line, at 5.1 m above sea level.

Why the times count

A point-to-point course that falls only counts for records within set limits, and London stays inside them: start and finish sit 10.7 km apart, a quarter of the race against a limit of half, and the course drops 0.86 m a kilometre against a limit of one. That is why the two world records set here in 2026 stand.

Beyond the dates, the day split and provisional start times, the 2027 race-week detail was not yet out when this was checked, so the practical sections below are how the 2026 race ran.

Saturday or Sunday: the 2027 Double

The 2027 race is a one-off format: 100,000 runners in total, 45,000 on Saturday 24 April and 55,000 on Sunday 25 April, each running on one day only, with no date changes. The organiser says the Saturday event is likely to start at 09:00 and the Sunday event at 09:30. The two days are not equal in time. Saturday is limited by road re-openings: the finish closes at 17:30, so the most time a Saturday runner has is 7 hours 45 minutes. On Sunday a secondary finish line in Green Park stays open until 23:59:59.

The weekend opens on Friday 23 April with the TCS Mini London Marathon, moved from its usual Saturday, and the Friday Night Lights event, currently planned for that evening. The deadline to defer from the Saturday event is 23:59:59 on Friday 23 April. Sunday entrants can defer until 23:59:59 on Saturday 24 April.

The Running Show and your pack

In 2026 packs were collected at the TCS London Marathon Running Show at ExCeL London, before a registration deadline of 17:30 on the Saturday, the day before the race. The organiser emailed each runner a unique QR code, and photo ID was required, such as a passport or driving licence. The pack held the non-transferable bib, the official kitbag and a kitbag sticker matching the bib number and baggage lorry. In 2026 one person could collect one other runner’s pack with their QR code, a signed letter and a photocopy of their ID. The 2027 registration page says the opposite: all runners must attend in person, and no one may pick up on their behalf. Plan to go yourself.

For 2027 the organiser is exploring an extra day, a Tuesday 20 to Saturday 24 April format, with the show open on Saturday 24 April while day one of the Double runs.

Getting to the start

Participants travelled free on race day in 2026 on Southeastern trains from London stations to the start, and on the DLR, Elizabeth line, Underground, Overground and buses: show the bib and do not tap in or out. The DLR started at about 05:30 from Tower Gateway and Lewisham and about 07:00 on its other routes. Thames Clippers river buses ran every 20 minutes from central London to Greenwich Pier.

The bib colour matches an assembly area, and each runner arrives at an allocated time. In 2026 the Blue and Red-on-yellow areas were a 10-minute walk from Blackheath station, the Pink a 10-minute walk from Maze Hill and the Red a 20-minute walk from Greenwich. The start is for participants only, and spectators were asked not to travel there.

Waves, bags and pacers

In 2026 start waves ran from about 09:30 to 11:30, set by predicted finish time, and all start lines closed at 11:30. A runner predicting a finish over seven hours started on the Pink Start.

Bags go to the allocated lorry, the one matching the number on the bib, and only the official kitbag is accepted. They come back in the finish area from the same lorry number. There was no bag drop in the Green Assembly Area. Pacers wait near the start line, each with a tall, bright flag on their back showing their finish time.

Aid on the course

The 2026 guide listed water refill stations at Miles 5, 10, 14, 17 and 20, and Buxton mineral water every three miles from Mile 3 to Mile 12, then every two miles from Mile 12 to Mile 24. Lucozade Sport came at Miles 7, 15, 21 and 23, and Lucozade Sport gels at Miles 13 and 19. The course clocks show the time since the first wave started, not a runner’s own time.

The finish

The line is on The Mall near Buckingham Palace, and the finish area spreads over Horse Guards Parade, with the information point and the bag lorries, and St James’s Park. In 2026 Westminster station was exit-only. The 2026 cut-off was eight hours after the last runner started at 11:30, with The Mall closing at 19:30 and the finish moving to St James’s Park until midnight.