Three Forts Challenge Half Marathon or Three Forts Challenge Marathon — which comes out ahead?

Three Forts Challenge Marathon has the stronger available profile on flat grade share and scenery score.

Route comparison snapshot

Three Forts Challenge Half Marathon

Mapped route
Held
Elevation profile
Held
course flatness
3.3% Favoured
flat grade share
29.5%
lower ascent
463 m
climbing density
21.9 m/km
net elevation
0 m
maximum grade
16.4%

Three Forts Challenge Marathon

Mapped route
Held
Elevation profile
Held
course flatness
3.5%
flat grade share
29.8% Favoured
lower ascent
922 m
climbing density
21.1 m/km
net elevation
-0 m
maximum grade
13.5%
Head-to-head comparison
MetricThree Forts Challenge Half MarathonThree Forts Challenge Marathon
Flat grade share29.5%29.8%
GAP factor (% slower than flat)3.3%3.5%
Uphill share35.1%35.8%
Steep-up share11.9%12.3%
Downhill share35.5%34.4%
Total ascent (m)463 m922 m
Climbing density (m/km)21.9 m/km21.1 m/km
Longest climb length (m)1,690 m3,550 m
Longest climb gain (m)99 m201 m
Longest climb average grade5.9%5.7%
Total descent (m)463 m922 m
Net elevation (m)0 m-0 m
Max absolute grade16.4%13.5%
Start elevation (m)7 m8 m
Finish elevation (m)7 m8 m
Scenic score68/10093/100
Conditions65/10065/100

Only metrics available for at least one side are shown. A ✓ marks the better value for each metric (higher-is-better aware). Scores are out of 100 when available. Ascent, climbing density, max absolute grade and median finish describe course or field context and are not marked as better or worse.

Same-distance comparisons are most meaningful; cross-distance metrics are contextual.

Race facts that change the decision

Race facts comparison
FactThree Forts Challenge Half MarathonThree Forts Challenge Marathon
Schedule

Exact race date not confirmed. Event weekend starts 2027-05-02 (legacy event-level date).

Exact race date not confirmed. Event weekend starts 2027-05-02 (legacy event-level date).

LocationLancing, South EastLancing, South East
Actual distance21.1 km43.8 km
raceindex.org mapped route heldHeldHeld
raceindex.org elevation profile heldHeldHeld
Course typeUnavailableLoop
SurfaceUnavailableHilly and challenging over chalk, flint and grass paths with stiles and rough tracks underfoot; minimal road sections.
Elevation characterHillyHilly
TerrainTrailTrail
SceneryCountryside, Historic, Coastal, RiversideCountryside, Historic, Coastal, Riverside
AtmosphereCommunity, Charity, Scenic TourCommunity, Charity, Scenic Tour
TechnicalityUnavailableModerate
Total ascent463 m922 m
Climbing density21.9 m/km21.1 m/km
Total descent463 m922 m
Net elevation0 m-0 m
Max absolute grade16.4%13.5%
Flat grade share29.5%29.8%
GAP factor3.3%3.5%
CutoffUnavailable6:00:00
Entry modelOpenOpen

Schedule

Three Forts Challenge Half Marathon

Exact race date not confirmed. Event weekend starts 2027-05-02 (legacy event-level date).

Three Forts Challenge Marathon

Exact race date not confirmed. Event weekend starts 2027-05-02 (legacy event-level date).

Location

Three Forts Challenge Half Marathon
Lancing, South East
Three Forts Challenge Marathon
Lancing, South East

Actual distance

Three Forts Challenge Half Marathon
21.1 km
Three Forts Challenge Marathon
43.8 km

raceindex.org mapped route held

Three Forts Challenge Half Marathon
Held
Three Forts Challenge Marathon
Held

raceindex.org elevation profile held

Three Forts Challenge Half Marathon
Held
Three Forts Challenge Marathon
Held

Course type

Three Forts Challenge Half Marathon
Unavailable
Three Forts Challenge Marathon
Loop

Surface

Three Forts Challenge Half Marathon
Unavailable
Three Forts Challenge Marathon
Hilly and challenging over chalk, flint and grass paths with stiles and rough tracks underfoot; minimal road sections.

Elevation character

Three Forts Challenge Half Marathon
Hilly
Three Forts Challenge Marathon
Hilly

Terrain

Three Forts Challenge Half Marathon
Trail
Three Forts Challenge Marathon
Trail

Scenery

Three Forts Challenge Half Marathon
Countryside, Historic, Coastal, Riverside
Three Forts Challenge Marathon
Countryside, Historic, Coastal, Riverside

Atmosphere

Three Forts Challenge Half Marathon
Community, Charity, Scenic Tour
Three Forts Challenge Marathon
Community, Charity, Scenic Tour

Technicality

Three Forts Challenge Half Marathon
Unavailable
Three Forts Challenge Marathon
Moderate

Total ascent

Three Forts Challenge Half Marathon
463 m
Three Forts Challenge Marathon
922 m

Climbing density

Three Forts Challenge Half Marathon
21.9 m/km
Three Forts Challenge Marathon
21.1 m/km

Total descent

Three Forts Challenge Half Marathon
463 m
Three Forts Challenge Marathon
922 m

Net elevation

Three Forts Challenge Half Marathon
0 m
Three Forts Challenge Marathon
-0 m

Max absolute grade

Three Forts Challenge Half Marathon
16.4%
Three Forts Challenge Marathon
13.5%

Flat grade share

Three Forts Challenge Half Marathon
29.5%
Three Forts Challenge Marathon
29.8%

GAP factor

Three Forts Challenge Half Marathon
3.3%
Three Forts Challenge Marathon
3.5%

Cutoff

Three Forts Challenge Half Marathon
Unavailable
Three Forts Challenge Marathon
6:00:00

Entry model

Three Forts Challenge Half Marathon
Open
Three Forts Challenge Marathon
Open

Facts are shown only when they exist in the sourced race record; Not held means no sourced value is held for that race.

Common questions

Which is flatter, Three Forts Challenge Half Marathon or Three Forts Challenge Marathon?

Three Forts Challenge Half Marathon has the lower GAP factor, making it the flatter course on our route model and more favourable on gradient alone.

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How figures are calculated →