Trail ultramarathon · South Korea

TransJeju by UTMB

2–4 October 2026 · Jeju Island, South Korea

Jeju100M: Fri, 2 October 2026

A Korean island ultra around Jeju with volcanic terrain, Hallasan-area climbing, coastal humidity, and strong Asia-Pacific trail demand.

Race day Weather, start logistics, and pacing execution are the only priorities.

Entry · Jeju100M · 2026 edition

Full: no places left

The organizer listed Jeju100M as full on 30 Sep 2026. A place can only come through the organizer's own transfer or waiting-list rules, if any.

From the organizer's page, checked 30 Sep 2026. TrailSplits does not know whether you have a place; the organizer is the final word.

Race Overview

TransJeju by UTMB is a trail ultramarathon scheduled for 2–4 October 2026 in Jeju Island, South Korea. TrailSplits currently includes 4 mapped courses for this event, with course maps, elevation profiles, weather context, and pacing tools for the uploaded GPX data.

How to get a place: First come, first served for the 2026 edition: registration opened 18 March 2026 (20K general from 20 March) and closes 31 July 2026. The 60K, 100K and 100M need a valid UTMB Index. Organizer's page, checked Wednesday 30 September 2026.

Race day
Date
2–4 October 2026
Type
Trail ultramarathon
Distances
4: Jeju100M, Jeju100K, Jeju60K, Jeju20K
Biggest course
148 km · +5,000 m vert
Cut-off
37 h (15.0 min/km)
Location
Jeju Island, South Korea
Jeju100M date
Fri, 2 October 2026
Entry
Open entry

TrailSplits is a free, independent route & pacing companion — not the official race. Visit the official TransJeju by UTMB site →

Finishing Jeju100M earns 4 Running Stones (100M category) toward the UTMB World Series Finals lottery. How Running Stones work.

Racing more than once next year? Add Jeju100M to a season and see whether your races work together.

Compare it with other races; no account needed.

Explore the Jeju100M course

Inspect the official course track on a topographic map, through its elevation profile, or in 3D.

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Min Max

running direction two lines: out and back on the same path kilometres

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Selected distance

Free training plan — Jeju100M

Vert-focused blueprint with route-finder links into the Planner.

Jeju100M plan 148 km · 5000 m D+

Prepare and return

Save Jeju100M to My Races

Keep this course, its training plan, calendar and future course updates together in your private My Races page. Saving does not publish your workouts, pace or progress.

Race route lab

Turn Jeju100M into a local rehearsal route

Open the official course in Planner, then choose a nearby start point to build a shorter loop that matches the course demand. This course averages about 33.8 m climb per km.

Race tools — Jeju100M

Fri, 2 October 2026

Race day

Send to your watch

Load the TransJeju by UTMB Jeju100M GPX onto your GPS watch

Get the official course as a clean GPX or a Garmin TCX course, with step-by-step instructions to load it onto a Garmin, COROS, Suunto, Wahoo, or Komoot — free, no account needed.

Send to watch

Compare your training

Compare your route to the TransJeju by UTMB Jeju100M course

See how faithfully your rehearsal route matches the real race. The official course for Jeju100M loads as Route A — upload your training route to compare distance, elevation gain, estimated time, and how much of the course you actually cover.

Compare to the course

Course analysis

Analyze the TransJeju by UTMB Jeju100M course — every climb

See the Jeju100M course broken into its major climbs and descents in order — length, gain, average grade, and steepness — so you know where the crux is and how to pace and fuel it.

Analyze the course

Race-week reminders

Get a nudge before TransJeju by UTMB

A free browser notification in the final week — the course crux, the weather window, and loading the GPX onto your watch. No app, no email, no account.

TransJeju by UTMB — frequently asked questions

When is TransJeju by UTMB 2026?

TransJeju by UTMB 2026 races run 2–4 October 2026 in Jeju Island, South Korea; the Jeju100M is on Fri, 2 October 2026. Check the official race site for registration deadlines and final details.

How long is TransJeju by UTMB and how much climbing is there?

4 distances (20–148 km). The longest course is 148 km with about 5,000 m of vertical gain — a demanding mountain course.

What is the cut-off time for TransJeju by UTMB?

The Jeju100M course has a 37-hour cut-off, an average of 15.0 min/km to finish in time. TrailSplits' cut-off pacer shows the buffer at each aid station.

Is there a free GPX and course map for TransJeju by UTMB?

Yes. TrailSplits gives you the course map, an interactive elevation profile, a 3D flyover and a downloadable GPX for every mapped distance — free and with no sign-up.

How do I train for TransJeju by UTMB?

Each distance has a free, course-specific 16-week training plan built around its distance, vertical gain and cut-offs, plus a pace and cut-off calculator.

Is TrailSplits the official TransJeju by UTMB website?

No. TrailSplits is a free, independent route and pacing companion. For registration and official rules, visit https://transjeju.utmb.world/.

Analyze this route in the Planner

Load the GPX directly into TrailSplits for surface analysis and terrain intel.