Three Forts Challenge 5 Mile or Three Forts Challenge Half Marathon — which comes out ahead?

Three Forts Challenge Half Marathon has the stronger available profile on flat grade share and course flatness.

Route comparison snapshot

Three Forts Challenge 5 Mile

Mapped route
Held
Elevation profile
Held
course flatness
3.6%
flat grade share
24.1%
lower ascent
172 m
climbing density
21.4 m/km
net elevation
0 m
maximum grade
14.8%

Three Forts Challenge Half Marathon

Mapped route
Held
Elevation profile
Held
course flatness
3.3% Favoured
flat grade share
29.5% Favoured
lower ascent
463 m
climbing density
21.9 m/km
net elevation
0 m
maximum grade
16.4%
Head-to-head comparison
MetricThree Forts Challenge 5 MileThree Forts Challenge Half Marathon
Flat grade share24.1%29.5%
GAP factor (% slower than flat)3.6%3.3%
Uphill share36.0%35.1%
Steep-up share10.5%11.9%
Downhill share39.9%35.5%
Total ascent (m)172 m463 m
Climbing density (m/km)21.4 m/km21.9 m/km
Longest climb length (m)1,370 m1,690 m
Longest climb gain (m)82 m99 m
Longest climb average grade6.0%5.9%
Total descent (m)172 m463 m
Net elevation (m)0 m0 m
Max absolute grade14.8%16.4%
Start elevation (m)6 m7 m
Finish elevation (m)6 m7 m
Scenic score68/10068/100
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 5 MileThree Forts Challenge Half 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 distance8 km21.1 km
raceindex.org mapped route heldHeldHeld
raceindex.org elevation profile heldHeldHeld
Elevation characterUnavailableHilly
TerrainTrailTrail
SceneryCountryside, Historic, Coastal, RiversideCountryside, Historic, Coastal, Riverside
AtmosphereCommunity, Charity, Scenic TourCommunity, Charity, Scenic Tour
Total ascent172 m463 m
Climbing density21.4 m/km21.9 m/km
Total descent172 m463 m
Net elevation0 m0 m
Max absolute grade14.8%16.4%
Flat grade share24.1%29.5%
GAP factor3.6%3.3%
Entry modelOpenOpen

Schedule

Three Forts Challenge 5 Mile

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

Three Forts Challenge Half Marathon

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

Location

Three Forts Challenge 5 Mile
Lancing, South East
Three Forts Challenge Half Marathon
Lancing, South East

Actual distance

Three Forts Challenge 5 Mile
8 km
Three Forts Challenge Half Marathon
21.1 km

raceindex.org mapped route held

Three Forts Challenge 5 Mile
Held
Three Forts Challenge Half Marathon
Held

raceindex.org elevation profile held

Three Forts Challenge 5 Mile
Held
Three Forts Challenge Half Marathon
Held

Elevation character

Three Forts Challenge 5 Mile
Unavailable
Three Forts Challenge Half Marathon
Hilly

Terrain

Three Forts Challenge 5 Mile
Trail
Three Forts Challenge Half Marathon
Trail

Scenery

Three Forts Challenge 5 Mile
Countryside, Historic, Coastal, Riverside
Three Forts Challenge Half Marathon
Countryside, Historic, Coastal, Riverside

Atmosphere

Three Forts Challenge 5 Mile
Community, Charity, Scenic Tour
Three Forts Challenge Half Marathon
Community, Charity, Scenic Tour

Total ascent

Three Forts Challenge 5 Mile
172 m
Three Forts Challenge Half Marathon
463 m

Climbing density

Three Forts Challenge 5 Mile
21.4 m/km
Three Forts Challenge Half Marathon
21.9 m/km

Total descent

Three Forts Challenge 5 Mile
172 m
Three Forts Challenge Half Marathon
463 m

Net elevation

Three Forts Challenge 5 Mile
0 m
Three Forts Challenge Half Marathon
0 m

Max absolute grade

Three Forts Challenge 5 Mile
14.8%
Three Forts Challenge Half Marathon
16.4%

Flat grade share

Three Forts Challenge 5 Mile
24.1%
Three Forts Challenge Half Marathon
29.5%

GAP factor

Three Forts Challenge 5 Mile
3.6%
Three Forts Challenge Half Marathon
3.3%

Entry model

Three Forts Challenge 5 Mile
Open
Three Forts Challenge Half 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 5 Mile or Three Forts Challenge Half 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.

Read the full pages

How figures are calculated →