London, GB · April 2027
TCS London Marathon
London Marathon pacing strategy with per-km splits for Greenwich-to-The-Mall, nutrition plan for the British spring, and race-week checklist.
- Distance
- 42.20 km
- Elevation gain
- 51 m
- Typical temp
- 5–14 °C
- Cutoff
- 8:00:00
The short version
A fair test with a few teeth
- Most runners crack near km 32 — fuel before km 30, not at it.
- Full overhead sun from km 5 — sunscreen and run the shaded side.
Next edition
25 April 2027
Typical race-day conditions
5–14 °C
We lock the real forecast into your plan in race week.
Course difficulty
ModerateDriven by a flat, fast course with mild conditions. Harder than Chevron Houston Marathon (4.5), easier than Generali München Marathon (4.5) — tougher than 21% of the races we cover.
Race data quality
Medium confidence
Auto-generated from GPS route + elevation data
Course distance, climate, and broad course features are suitable for pacing previews. Elevation profiles and aid-station details are approximate and should be checked against the official race packet before race day.
Elevation profile
Route-derived (GPX + DEM)
Paid strategy guardrail
Official race packet remains source of truth
- Open-Meteo historical climate archive (2022–2024)
Step 1 · Free preview
See the course-adjusted plan first
Enter one recent result. The preview returns course cost, first splits, and fuel target from the deterministic engine and the current course data model.
VDOT
49.1
Estimate
3:13:35
Course cost
-0:10
Fuel target
60 g/h
60 g/h needs a trained gut — practise it in training, never try new fuelling on race day. Your full plan tunes this to your experience.
First 5 km preview
full race locked
- km 14:45
- km 24:46
- km 34:41
- km 44:44
- km 54:29
First race free · then €7 Race Pass · no monthly subscription
Uses an approximate course model; verify final logistics against the official race packet.
Step 2 · Your full TCS London Marathon plan
The preview shows the shape. The plan races it for you.
Course preview
Free
what you see now
- Difficulty score & course data
- Course-cost & toughest km
- Your first full plan free, ever
Race Pass
€7
one-time, this race
- Every km split, weather-adjusted
- Nutrition & fluid timeline
- Heat, wind & sun race tactics
- Danger zones + watch file (GPX)
- Race-week forecast & reminders
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€19
per year, every race
- Everything in Race Pass
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Continue with approximate course data →Course elevation
51 m total gain · 84 m loss · max 54 m, min 1 m.
Fly the course
Sun & shade
Sun in your eyes
6 km
Sun on your back
12 km
Side / overhead
24 km
From km 5 the sun sits high overhead — peak UV and radiant heat, so keep sunscreen on and run the shaded side of the road where you can.
Approximate — solar position from the route geometry and a 09:40:00 start (timezone estimated from longitude), for a mid-pack finishing time.
Signature sections
Tower Bridge · km 19–19.5
Crossing the Thames at halfway — flat, but a psychological anchor point.
Embankment to The Mall · km 39–42.195
Final stretch along the river, past Big Ben, finishing on The Mall.
Aid stations
8 stations on course — plan your fueling around them.
Race overview
London is a fast, well-supported course with three separate starts that converge at km 5. Slight net downhill (about 28 m) over the full distance, gentle undulations through Greenwich, Tower Bridge at halfway, then a flat final 10 km along the Thames Embankment to The Mall. April weather averages 7–15 °C — close to ideal for marathon physiology — though wind off the river in the final kilometres can be a factor for sub-3-hour runners. Pace evenly, fuel from km 10, and save effort for the long, flat closing stretch through central London.
How hard is this course?
Reference table — how the TCS London Marathon compares to a flat sea-level course for four typical fitness levels. Computed from the route profile, mean course altitude, and typical race-week climate (10 °C / 74 % humidity). Your personal strategy uses your VDOT, per-km splits, nutrition timing, and the typical climate baseline for this static sample; paid strategies use Open-Meteo when a verified race date is inside the forecast window.
| Runner | Flat-course finish | TCS London Marathon finish | Course cost | Adjusted pace |
|---|---|---|---|---|
| Beginner (VDOT 35) | 4:16:08 | 4:15:55 | -0.1% | 6:04/km |
| Intermediate (VDOT 45) | 3:28:17 | 3:28:07 | -0.1% | 4:56/km |
| Trained (VDOT 50) | 3:10:41 | 3:10:31 | -0.1% | 4:31/km |
| Competitive (VDOT 60) | 2:43:24 | 2:43:15 | -0.1% | 3:53/km |
Reference nutrition
For a 70 kg runner finishing in 3:10:31 at 10 °C. Adjust to your weight and tolerance — these are ISSN-window targets, not prescriptions.
- Carbs / hour
- 60 g
- Total carbs
- 191 g
- Fluid / hour
- 640 ml
- Sodium / hour
- 500 mg
FAQ
Is London fast?
Yes. 102 m of cumulative gain, slight net downhill, mostly flat after the rolling first 8 km. World records have been set here.
Where do the three London starts join?
Red, blue, and green starts converge at roughly km 4.7 in Woolwich. From there the course is one road to The Mall.
Get your personalized strategy
The numbers above are samples. Sign up free and get the full TCS London Marathon strategy from your VDOT, the current course model, Open-Meteo race-week forecast when available, and your nutrition preferences.
First race free · €7 per additional race · €19/yr for unlimited
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New to the marathon? Start with our marathon pacing strategy guide or run the VDOT calculator.