Biggest marathons by field size
Field size is a pacing variable, not just a statistic. In a field of 50,000 the first two kilometres are congested enough to cost you real time, aid stations are crowded, and the temptation to burn matches passing people is constant — which is why the negative-split advice that works at a 3,000-runner race needs adjusting at a Major. Ranked by the number of runners on the start line.
The ranking
| # | Course | Location | Measure |
|---|---|---|---|
| 1 | Berlin Marathon | Berlin | ≈55,000 runners |
| 2 | New York City Marathon | New York, NY | ≈55,000 runners |
| 3 | Paris Marathon | Paris | ≈55,000 runners |
| 4 | Chicago Marathon | Chicago, IL | ≈52,000 runners |
| 5 | London Marathon | London | ≈50,000 runners |
| 6 | Manchester Marathon | Manchester | ≈40,000 runners |
| 7 | Tokyo Marathon | Tokyo | ≈38,000 runners |
| 8 | Valencia Marathon | Valencia | ≈35,000 runners |
| 9 | Osaka Marathon | Osaka | ≈34,000 runners |
| 10 | Boston Marathon | Boston, MA | ≈30,000 runners |
| 11 | Philadelphia Marathon | Philadelphia, PA | ≈30,000 runners |
| 12 | Rome Marathon | Rome | ≈30,000 runners |
| 13 | Marine Corps Marathon | Arlington, VA | ≈30,000 runners |
| 14 | Mexico City Marathon | Mexico City | ≈30,000 runners |
| 15 | Barcelona Marathon | Barcelona | ≈28,000 runners |
| 16 | Los Angeles Marathon | Los Angeles, CA | ≈27,000 runners |
| 17 | Sydney Marathon | Sydney, NSW | ≈25,000 runners |
| 18 | Honolulu Marathon | Honolulu, HI | ≈25,000 runners |
| 19 | Detroit Free Press Marathon | Detroit, MI | ≈23,000 runners |
| 20 | Dublin Marathon | Dublin | ≈22,500 runners |
Frequently asked questions
Biggest marathons by field size: which is number one?
Berlin Marathon — ≈55,000 runners. The full ranking covers 20 courses and is computed from each course's own elevation profile rather than from race organiser claims.
How are these rankings calculated?
From the elevation profile of each course, built from GPX traces and digital elevation models, clipped to the official 42.195 km. Elevation figures carry roughly ±5–10 m of DEM noise, so small differences between flat courses are measurement error rather than a meaningful gap.
Other course rankings
- The Flattest Marathon Courses — Courses ranked by total elevation gain, least first.
- The Hilliest Marathon Courses — Courses ranked by total elevation gain, most first.
- Net-Downhill Marathon Courses — Courses ranked by net elevation change, biggest drop first.
- Marathons With the Hardest Finish — Courses whose toughest stretch lands after 30 km, ranked by how hard it bites.
- World Marathon Majors: Course Profiles Compared — Every Major course, ranked flattest to hilliest.