100K ultra runs
A 100K ultra pushes runners into full ultra-distance territory. These demanding events test endurance, pacing and mental resilience across long hours on the trail. Use the filters to find 100K ultras by date, location or terrain. Read more
A 100K ultra run covers around 62 miles and is a major step up from shorter ultra distances. These events often include significant elevation, technical terrain and long cut-off times, requiring careful preparation and race strategy.
Many 100K ultras are trail-based and take runners through remote landscapes, mountain paths or long point-to-point routes. Aid stations, navigation and mandatory kit play a bigger role at this distance.
If you’re working up to something even bigger, explore our 100-mile ultra events — the ultimate endurance challenge in ultra running.
Want to read more? Read the guides, tips and advice from our blog.
Got questions? Read our FAQs for answers.
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Map view100K ultra runs 2026–2027
Discover 100K ultras across the UK and beyond and get ready for your next start line.
- Sat 25 Apr
- £90.50
North Wales 100K
This event gives participants the opportunity to take in a runnable, beautiful route which follows the North Walian coastline between Prestatyn and Bangor.
- 100 km trail running + 8000 ft ascent
- Sat 20 Jun
- £175
Race to the King | 100K Non-Stop
The full circuit takes in both the Coastal and Castle loops for a magnificent tour of the stunning South Downs. Steeped in history and uniquely varied, the 100K offers a course truly fit for royalty.
- 100 km trail running + 1510 m ascent
- Sat 11 - Sun 12 Jul
- £90-£275
Race to the Stones
Travel across the Ridgeway, the UK’s oldest footpath, pass through ancient landscapes, and end at the iconic Avebury Standing Stones. This is a journey on foot through 5000 years of history.
- 50K ultra run 2
- 100K ultra run 3
- Sat 11 - Sun 12 Jul
- £129.99-£319.99
Black Diamond Yr Wyddfa Snowdon24
Yr Wyddfa (Snowdon) is the highest mountain in England and Wales. Your challenge is to ascend and descend as many times as possible in 24 hours - solo or as a relay team.
- 24 hrs trail running + 3182 ft ascent
- Fri 18 Sep
- From £86
Peak District Challenge | Gold Ultra 100K
A hilly and challenging route showcasing the best of the Peak District for those who can maintain 4kph over 24 hours. Night navigation experience is essential.
- 100 km trail running + 3300 m ascent
- Sat 19 - Sun 20 Sep
- £140-£200
Skyline Scotland | Skyline Scotland 100K
A runnable 100km with a Scottish Highland journey at the heart of the race experience with an exciting midnight mass start.
- 106 km trail running + 6350 m ascent
- Sun 22 Mar
- £90-£120
Canalathon-Ultra Running Festival | 100K
Enter this deliciously scenic romp over distances of 100km, 50km, Half Marathon or 10km. Go big or stay home!
- 100 km road running + 377 m ascent
- Sat 2 - Sun 3 May
- £39-£199
Isle of Wight Ultra Challenge
Great challenges need great settings, and up to 2,000 adventurers will take on the Isle of Wight stunning coastal path – all out to push themselves further this year!
- Trail run 3
- 50K ultra run 3
- 100K ultra run 2
- Ultra run
- Sun 3 May
- £77
Tempo Trail Races | 100K Ultra
Tempo Trail Races 2026 are open for entry!!!
- 100 km trail running + 6682 ft ascent
- Sat 9 May
- £118-£120
Chiltern Hills 100K
A 100K ultra marathon along the best and most loved trails within the Chiltern Hills.
- 100 km trail running
- Sat 16 - Sun 17 May
- £39-£199
Jurassic Coast Ultra Challenge
Walk, jog or run along the spectacular UNESCO World Heritage coastline from Corfe Castle past Lulworth Cove and Durdle Door, with full support, welcoming base camp and finish line celebration!
- Trail run 2
- 50K ultra run 2
- 100K ultra run 2
- Marathon
- Ultra run
- + 1 more race
- Sat 23 - Sun 24 May
- £89-£199
London 2 Brighton Ultra Challenge
Walk, jog or run the capital-to-coast route with 2,000 other adventurers over a range of distance options available and superb support all the way, for all abilities and experience levels.
- Trail run 3
- Ultra run 2
- Marathon
- 100K ultra run 2
- Sat 6 - Sun 7 Jun
- £39-£199
Lake District Ultra Challenge
Take on England’s finest countryside at your own pace with stunning views all the way, featuring the Garburn Pass, historic Ambleside, a halfway point by Lake Windermere, forests and nature reserves.
- Trail run 2
- 50K ultra run 2
- 100K ultra run 2
- Marathon
- Sat 13 - Sun 14 Jun
- £39-£199
Cotswold Way Ultra Challenge
Challenge yourself in the rolling hills of the Cotswolds featuring the Cotswold Way itself, villages, footpaths and trails with fabulous views on route plus full support and hospitality.
- Trail run 2
- Ultra run 4
- 100K ultra run
- 10K run
- Sat 20 - Sun 21 Jun
- £49-£199
North Yorks Ultra Challenge
Set to be one of the greatest Ultra Challenges – basecamp is in Scarborough – famous for its Fair, and a popular seaside spa since the 17th century.
- 100K ultra run 2
- 50K ultra run 2
- Trail run
- 10 miler
- Sat 20 Jun
- £20-£100
Two Rose Ultra | Two Roses Ultra - 100K
An ultramarathon with a difference, The usual ultra set-up with a bit extra thrown in: this unique event offers you a choice between two 50km loops or the full 100km.
- 100 km multi terrain running + 5175 ft ascent
- Sat 20 Jun
- £118
Jurassic Coast 100K Ultra
Jurassic Coast 100K Ultra
- 100 km trail running + 2900 m ascent
- Fri 3 - Sat 4 Jul
- £103-£105
The Full Essex Way Ultra
Starting at Epping tube station in London and finishing at the high lighthouse in the historic port of Harwich, the ultra covers the full 82 miles of the beautiful Essex Way Trail.
- 82 miles trail running + 3469 ft ascent
- Sat 4 - Sun 5 Jul
- £49-£199
Peak District Ultra Challenge
From the idyllic basecamp hub in Bakewell, charity challengers will head into the fabulous Peak District National Park on a route from 10 miles right up to the full 100km with full support!
- Ultra run 3
- 100K ultra run 2
- Trail run 2
- Sat 18 - Sun 19 Jul
- £49-£199
Gower Peninsula Ultra Challenge
A new Ultra Challenge for this year, set on the stunning Gower Peninsula – the UK’s first Area of Outstanding Natural Beauty and famous for its golden beaches.
- 100K ultra run 2
- Ultra run
- 50K ultra run 2
- Marathon
- Multi-terrain run
- + 1 more race
- Sat 5 - Sun 6 Sep
- £89-£199
South Coast Ultra Challenge
The South Downs National Park is a superb backdrop for a real challenge featuring Beachy Head, the Seven Sisters and the South Downs Way with a choice of distances from 25km right up to 100km!
- 100K ultra run 2
- Ultra run 2
- Trail run
- Mon 7 - Sat 12 Sep
- £1,699-£2,099
Dragon’s Back Race
Considered to be one of the toughest mountain races in the world, participants attempting the Full Course will need to cover 380km with 16,400m of ascent along the Dragon’s Back of Wales.
- 6 days fell running
- Fri 11 - Sun 13 Sep
- £39-£199
Thames Path Ultra Challenge
England’s greatest river provides a fantastic backdrop for an unforgettable 'festival' challenge weekend, with distances from 10km right up to 100km there’s a Thames Challenge for everyone!
- 100K ultra run 2
- 50K ultra run 2
- Trail run 4
- Ultra run
- 10K run
- + 4 more races
- Sat 12 Sep
- £25-£27
Leeds Country Way In A Day 100K
The Leeds Country Way In a Day 100km is a full circumnavigation of the city of Leeds via the local LCW footpaths.
- 100K ultra run 2
- Sat 3 Oct
- £95
Cornwall's Backyard Ultra
Cornwall’s Backyard Ultra isn’t just a race. It’s a community. A personal test. A party. A game. And everyone’s invited.
- 4.17 miles multi terrain running
100K ultra marathon blog
Guides, tips and advice on running a 100K ultra.
- 10 mins read
Race 101: the 13 Valleys Ultra
Introducing the 13 Valleys Ultra plus the event's shorter distance options, helping you to push your limits and get involved!
- 8 mins read
10 best ultra marathons in the UK
Take on an epic endurance challenge with one of the most popular ultra runs in the UK, from traditional fell runs to the UTMB World Series!
100K ultra marathon FAQs
Answers to the most common questions about running a 100K ultra marathon.
A 100K ultra is approximately 62 miles, often taking runners many hours to complete.
Most 100K events recommend prior marathon or ultra experience due to distance, terrain and cut-off times.
Completion times vary widely due to the different terrain - some of the easier events can be completed in 12-15 hours, some of the mountainous events can take 1-2 days.
100K ultra runs near you
Select your location for 100K ultra marathons in your area.