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About RaceIndexOur methodologyData coverageCyclingTriathlon

Lowest GAP factor ultramarathons

The lowest gap factor ultramarathons, ranked from trusted raw-elevation route profiles across 67 qualifying races.

Ranking current as of

Which race ranks first — and why is it McKenzie River Trail Run 50K?

McKenzie River Trail Run 50K leads this ranking on gap factor (-1.5%).

Compare McKenzie River Trail Run 50K vs Daytona 100 Ultramarathon (Jacksonville Beach to Ponce Inlet)

#RaceGAP factorAscentClimb densityDescentNet elevationMax absolute gradeFeeAs of
1McKenzie River Trail Run 50K Ultramarathon - oregon-1.5%535 m10.7 m/km892 m-357 m22.4%Unavailable
2Daytona 100 Ultramarathon (Jacksonville Beach to Ponce Inlet) - florida-0.0%39 m0.2 m/km40 m-1 m1.7%Unavailable
3Stort30 Ultramarathon - east-of-england0.1%99 m2.0 m/km98 m0 m7.1%£55
4Bath & Bristol Railway Races Ultramarathon - south-west0.1%136 m2.7 m/km135 m1 m6.7%£65
5Endurancelife Suffolk (Dunwich) Ultramarathon - east-of-england0.3%247 m4.7 m/km246 m0 m8.4%£71
6Thames Path 100 Ultramarathon - south-east0.4%222 m1.4 m/km174 m48 m11.9%£225
7The Pistol Ultra (Alcoa) - tennessee0.4%696 m4.3 m/km696 m-0 m12.1%Unavailable
8North Downs Way 100 Ultramarathon - south-east0.4%155 m0.9 m/km95 m59 m20.8%£220
9Kettle Moraine 100 Endurance Runs Ultramarathon - wisconsin0.6%1,034 m6.4 m/km1,034 m-0 m16.3%Unavailable
10Flint Hills 50 and Marathon Ultramarathon - kansas0.6%655 m8.1 m/km656 m-1 m9.6%Unavailable
11NN Ultrabalaton Ultramarathon - hungary1.0%3,407 m8.2 m/km3,408 m-1 m22.6%Unavailable
12Autumn 100 Ultramarathon - south-east1.0%1,380 m8.6 m/km1,381 m-1 m21.3%£220
13Gravel Worlds Run Series (Lincoln) Ultramarathon - nebraska1.1%589 m11.8 m/km588 m1 m8.9%Unavailable
14The Wall Ultramarathon - north-east1.2%1,140 m10.2 m/km1,158 m-18 m15.8%£230
15The Hawk Hundred (Lawrence) Ultramarathon - kansas1.2%1,527 m9.5 m/km1,518 m8 m15.2%Unavailable
16Lean Horse Ultra Marathon - south-dakota1.3%1,791 m11.1 m/km1,781 m10 m26.2%Unavailable
17Run Woodstock Ultramarathon - michigan1.3%1,764 m11.0 m/km1,763 m1 m10.2%Unavailable
18TARC Stone Cat Trail Festival Ultramarathon - massachusetts1.4%1,094 m10.9 m/km1,095 m-0 m17.4%Unavailable
19Norfolk Festival of Running (King's Lynn) Ultramarathon - east-of-england1.6%627 m12.5 m/km628 m-1 m9.8%£38
20Connemara International Marathon (Connemarathon) Ultramarathon - ireland1.8%755 m11.9 m/km732 m23 m19.4%Unavailable
21Race to the Stones Ultramarathon - south-east1.9%1,260 m12.6 m/km1,228 m32 m19.4%Unavailable
22Running with the Devil (Las Vegas) Ultramarathon - nevada2.0%839 m16.8 m/km839 m0 m21.6%Unavailable
23Gower Coastal Trail Races Ultramarathon - wales2.0%1,087 m13.5 m/km1,088 m-1 m23.7%£85
24Ring O' Fire Ultramarathon - wales2.0%2,480 m11.9 m/km2,479 m1 m39.1%£255
25Race to the King Ultramarathon - south-east2.6%1,434 m13.9 m/km1,434 m0 m18.8%£155
26Reims Champagne Run Ultramarathon - france2.8%1,343 m15.4 m/km1,333 m9 m21.0%Unavailable
27Cairngorms Ultra Trail - scotland2.8%948 m15.8 m/km949 m-1 m25.0%£67
28Ice Age Trail 50 Ultramarathon - wisconsin2.9%1,263 m15.7 m/km1,263 m0 m22.6%Unavailable
29Lake Tahoe Marathon Ultramarathon - nevada3.1%1,912 m16.5 m/km1,939 m-27 m44.7%Unavailable
30Holiday Lake 50K (Appomattox) Ultramarathon - virginia3.2%810 m16.2 m/km799 m11 m35.7%Unavailable
31West Highland Way Race Ultramarathon - scotland3.5%2,703 m17.7 m/km2,748 m-46 m32.9%£157
32HOKA Bandera Endurance Trail Race Ultramarathon - texas3.5%1,711 m17.1 m/km1,734 m-23 m29.3%Unavailable
33Mohican Trail 100 Mile Run Ultramarathon - ohio3.7%2,890 m18.0 m/km2,883 m7 m30.8%Unavailable
34Spokane River Run Ultramarathon - washington3.8%925 m18.5 m/km925 m0 m25.9%Unavailable
35South Downs Way 100 Ultramarathon - south-east4.1%3,410 m21.2 m/km3,504 m-94 m31.8%£220
36Minnesota Voyageur Trail Ultramarathon - minnesota4.1%1,484 m18.4 m/km1,484 m-0 m36.5%Unavailable
37Devil o' the Highlands Footrace Ultramarathon - scotland4.4%1,641 m23.8 m/km1,876 m-235 m28.9%£100
38Bimbler's Bluff 50K Ultramarathon - connecticut4.7%1,092 m21.8 m/km1,092 m-0 m39.4%Unavailable
39Maah Daah Hey Trail Run (Medora) Ultramarathon - north-dakota4.9%2,080 m25.9 m/km2,085 m-5 m27.7%Unavailable
40Chiltern Wonderland 50 Ultramarathon - south-east5.0%1,699 m21.0 m/km1,694 m5 m39.0%£115
41Endurancelife Pembrokeshire Ultramarathon - wales5.2%1,270 m22.8 m/km1,269 m1 m29.0%Unavailable
42Sheltowee Trace Ultras (Big Turtle Trail Runs), Morehead - kentucky5.5%1,187 m14.8 m/km1,182 m5 m23.2%Unavailable
43Tollymore Extreme (Tollymore Trail Marathon), Newcastle Ultramarathon - northern-ireland5.5%1,630 m25.9 m/km1,638 m-8 m28.1%Unavailable
44Two Tunnels Railway Races Ultramarathon - south-west5.6%1,231 m24.6 m/km1,229 m2 m17.3%£65
45Beachy Head Marathon Ultramarathon - south-east5.7%1,308 m24.9 m/km1,305 m2 m31.2%Unavailable
46Endurancelife Coastal Trail Series - North York Moors (Ravenscar) Ultramarathon - yorkshire5.7%1,310 m23.7 m/km1,310 m0 m28.3%£71
47Western States Endurance Run Ultramarathon - california5.7%4,960 m30.8 m/km6,466 m-1,506 m39.2%Unavailable
48Tecumseh Trail Marathon (Tecumseh Trail Challenge), Nashville Indiana Ultramarathon - indiana5.8%1,196 m23.9 m/km1,195 m0 m24.5%Unavailable
49Highland Fling Race (Milngavie) Ultramarathon - scotland6.1%1,939 m22.8 m/km1,758 m181 m29.5%£125
50Patapsco Valley 50K Ultramarathon - maryland6.6%1,387 m27.7 m/km1,394 m-6 m31.6%Unavailable
51Arc of Attrition Ultramarathon - south-west7.2%4,116 m25.5 m/km4,038 m78 m43.9%£239
52Wild Duluth Races Ultramarathon - minnesota8.0%2,801 m28.0 m/km2,801 m-0 m35.8%Unavailable
53Massanutten Mountain Trails 100 Mile Run Ultramarathon - virginia8.1%4,799 m29.6 m/km4,799 m0 m35.1%Unavailable
54Endurancelife Classic Quarter (Cornwall Coastal Ultra) - south-west8.3%1,916 m27.1 m/km1,884 m31 m45.0%Unavailable
55Tahoe Rim Trail Endurance Runs Ultramarathon - nevada8.4%5,117 m31.2 m/km5,117 m-0 m34.8%Unavailable
56The Malvern Hills Ultra - west-midlands8.5%2,391 m31.6 m/km2,391 m0 m36.3%£95
57Chuckanut 50k Ultramarathon - washington8.6%1,416 m28.3 m/km1,422 m-5 m34.9%Unavailable
58Silver State 50/50 (Reno) Ultramarathon - nevada8.6%2,716 m33.8 m/km2,717 m-1 m36.7%Unavailable
59Leadville Trail 100 Run Ultramarathon - colorado8.9%4,444 m27.7 m/km4,445 m-0 m42.6%Unavailable
60Kia Fjällmaraton (Fjällmaratonveckan), Årefjällen Ultramarathon - sweden9.8%3,203 m32.0 m/km3,175 m29 m41.7%Unavailable
61Worlds End Ultramarathon - pennsylvania10.4%3,319 m33.2 m/km3,320 m-1 m37.1%Unavailable
62Scout Mountain Ultras - idaho11.3%6,262 m38.0 m/km6,271 m-8 m39.4%Unavailable
63Tamalpa Headlands 50K Ultramarathon - california11.6%1,966 m39.3 m/km1,967 m-1 m43.2%Unavailable
64SciaccheTrail – Cinque Terre Ultra Trail - italy15.5%4,300 m42.4 m/km4,334 m-34 m40.1%Unavailable
65Endurancelife Peak District (Castleton) Ultramarathon - east-midlands16.2%2,126 m41.7 m/km2,127 m-0 m42.6%Unavailable
66Transvulcania Ultramarathon - spain25.1%4,128 m56.5 m/km3,796 m332 m38.8%Unavailable
67Gornergrat Zermatt Marathon Ultramarathon - switzerland32.4%2,408 m52.8 m/km404 m2,004 m32.0%Unavailable
3
Stort30 Ultramarathoneast-of-england
GAP factor
0.1%
Ascent
99 m
Climb density
2.0 m/km
Descent
98 m
Net elevation
0 m
Max absolute grade
7.1%
Fee
£55

As of

6
Thames Path 100 Ultramarathonsouth-east
GAP factor
0.4%
Ascent
222 m
Climb density
1.4 m/km
Descent
174 m
Net elevation
48 m
Max absolute grade
11.9%
Fee
£225

As of

7
The Pistol Ultra (Alcoa)tennessee
GAP factor
0.4%
Ascent
696 m
Climb density
4.3 m/km
Descent
696 m
Net elevation
-0 m
Max absolute grade
12.1%
Fee
Unavailable

As of

8
North Downs Way 100 Ultramarathonsouth-east
GAP factor
0.4%
Ascent
155 m
Climb density
0.9 m/km
Descent
95 m
Net elevation
59 m
Max absolute grade
20.8%
Fee
£220

As of

11
NN Ultrabalaton Ultramarathonhungary
GAP factor
1.0%
Ascent
3,407 m
Climb density
8.2 m/km
Descent
3,408 m
Net elevation
-1 m
Max absolute grade
22.6%
Fee
Unavailable

As of

12
Autumn 100 Ultramarathonsouth-east
GAP factor
1.0%
Ascent
1,380 m
Climb density
8.6 m/km
Descent
1,381 m
Net elevation
-1 m
Max absolute grade
21.3%
Fee
£220

As of

14
The Wall Ultramarathonnorth-east
GAP factor
1.2%
Ascent
1,140 m
Climb density
10.2 m/km
Descent
1,158 m
Net elevation
-18 m
Max absolute grade
15.8%
Fee
£230

As of

16
Lean Horse Ultra Marathonsouth-dakota
GAP factor
1.3%
Ascent
1,791 m
Climb density
11.1 m/km
Descent
1,781 m
Net elevation
10 m
Max absolute grade
26.2%
Fee
Unavailable

As of

17
Run Woodstock Ultramarathonmichigan
GAP factor
1.3%
Ascent
1,764 m
Climb density
11.0 m/km
Descent
1,763 m
Net elevation
1 m
Max absolute grade
10.2%
Fee
Unavailable

As of

21
Race to the Stones Ultramarathonsouth-east
GAP factor
1.9%
Ascent
1,260 m
Climb density
12.6 m/km
Descent
1,228 m
Net elevation
32 m
Max absolute grade
19.4%
Fee
Unavailable

As of

24
Ring O' Fire Ultramarathonwales
GAP factor
2.0%
Ascent
2,480 m
Climb density
11.9 m/km
Descent
2,479 m
Net elevation
1 m
Max absolute grade
39.1%
Fee
£255

As of

25
Race to the King Ultramarathonsouth-east
GAP factor
2.6%
Ascent
1,434 m
Climb density
13.9 m/km
Descent
1,434 m
Net elevation
0 m
Max absolute grade
18.8%
Fee
£155

As of

26
Reims Champagne Run Ultramarathonfrance
GAP factor
2.8%
Ascent
1,343 m
Climb density
15.4 m/km
Descent
1,333 m
Net elevation
9 m
Max absolute grade
21.0%
Fee
Unavailable

As of

27
Cairngorms Ultra Trailscotland
GAP factor
2.8%
Ascent
948 m
Climb density
15.8 m/km
Descent
949 m
Net elevation
-1 m
Max absolute grade
25.0%
Fee
£67

As of

28
Ice Age Trail 50 Ultramarathonwisconsin
GAP factor
2.9%
Ascent
1,263 m
Climb density
15.7 m/km
Descent
1,263 m
Net elevation
0 m
Max absolute grade
22.6%
Fee
Unavailable

As of

29
Lake Tahoe Marathon Ultramarathonnevada
GAP factor
3.1%
Ascent
1,912 m
Climb density
16.5 m/km
Descent
1,939 m
Net elevation
-27 m
Max absolute grade
44.7%
Fee
Unavailable

As of

34
Spokane River Run Ultramarathonwashington
GAP factor
3.8%
Ascent
925 m
Climb density
18.5 m/km
Descent
925 m
Net elevation
0 m
Max absolute grade
25.9%
Fee
Unavailable

As of

35
South Downs Way 100 Ultramarathonsouth-east
GAP factor
4.1%
Ascent
3,410 m
Climb density
21.2 m/km
Descent
3,504 m
Net elevation
-94 m
Max absolute grade
31.8%
Fee
£220

As of

38
Bimbler's Bluff 50K Ultramarathonconnecticut
GAP factor
4.7%
Ascent
1,092 m
Climb density
21.8 m/km
Descent
1,092 m
Net elevation
-0 m
Max absolute grade
39.4%
Fee
Unavailable

As of

45
Beachy Head Marathon Ultramarathonsouth-east
GAP factor
5.7%
Ascent
1,308 m
Climb density
24.9 m/km
Descent
1,305 m
Net elevation
2 m
Max absolute grade
31.2%
Fee
Unavailable

As of

50
Patapsco Valley 50K Ultramarathonmaryland
GAP factor
6.6%
Ascent
1,387 m
Climb density
27.7 m/km
Descent
1,394 m
Net elevation
-6 m
Max absolute grade
31.6%
Fee
Unavailable

As of

51
Arc of Attrition Ultramarathonsouth-west
GAP factor
7.2%
Ascent
4,116 m
Climb density
25.5 m/km
Descent
4,038 m
Net elevation
78 m
Max absolute grade
43.9%
Fee
£239

As of

52
Wild Duluth Races Ultramarathonminnesota
GAP factor
8.0%
Ascent
2,801 m
Climb density
28.0 m/km
Descent
2,801 m
Net elevation
-0 m
Max absolute grade
35.8%
Fee
Unavailable

As of

56
The Malvern Hills Ultrawest-midlands
GAP factor
8.5%
Ascent
2,391 m
Climb density
31.6 m/km
Descent
2,391 m
Net elevation
0 m
Max absolute grade
36.3%
Fee
£95

As of

57
Chuckanut 50k Ultramarathonwashington
GAP factor
8.6%
Ascent
1,416 m
Climb density
28.3 m/km
Descent
1,422 m
Net elevation
-5 m
Max absolute grade
34.9%
Fee
Unavailable

As of

61
Worlds End Ultramarathonpennsylvania
GAP factor
10.4%
Ascent
3,319 m
Climb density
33.2 m/km
Descent
3,320 m
Net elevation
-1 m
Max absolute grade
37.1%
Fee
Unavailable

As of

62
Scout Mountain Ultrasidaho
GAP factor
11.3%
Ascent
6,262 m
Climb density
38.0 m/km
Descent
6,271 m
Net elevation
-8 m
Max absolute grade
39.4%
Fee
Unavailable

As of

63
Tamalpa Headlands 50K Ultramarathoncalifornia
GAP factor
11.6%
Ascent
1,966 m
Climb density
39.3 m/km
Descent
1,967 m
Net elevation
-1 m
Max absolute grade
43.2%
Fee
Unavailable

As of

66
Transvulcania Ultramarathonspain
GAP factor
25.1%
Ascent
4,128 m
Climb density
56.5 m/km
Descent
3,796 m
Net elevation
332 m
Max absolute grade
38.8%
Fee
Unavailable

As of

67 qualifying races in this ranking; use the distance catalogue to search the full distance list. Scores are out of 100 when present; route, elevation and cost figures are shown in their natural units.

How we ranked these

Races are ranked by GAP factor. Score metrics use methodology scoring-methodology-v1.0. Elevation rankings use only trusted raw-elevation course profiles. A ranking is only published when at least five races qualify, so the table is never padded with thin data.

See exactly how each figure is calculated →

Route maps for this ranking

How we calculated this

Published facts and derived model outputs on this page are tied to stored sources or a published, version-locked methodology. We show the provenance so runners, coaches and organisers can check it. Data on this page is current as of .

Derived numbers use scoring-methodology-v1.0.

Sources used on this page (69)

Read the full methodology →

Common questions

What is the lowest gap factor ultramarathons?

McKenzie River Trail Run 50K Ultramarathon ranks first by gap factor, from 67 qualifying races compared under our published methodology.