Istria 100 by UTMB - 110K

Istria 110K Finish Time Predictor

Istria 110K race stats pre-loaded (111 km, 4,200 m D+). Enter a known race result to get an elevation-adjusted finish time estimate.

111km4,200m D+Winner: ~9h27Cutoff: 28h

Full Istria 100 by UTMB - 110K course data: aid stations, cutoffs, course profile

1. Your race

Istria 110K

111 km · 4200 m D+ · 4272 m D-

Different race?

Have the GPX? Measure the exact course in the GPX Explorer

2. How should we estimate you?

From my Strava historyYour last 90 days of real training. Opens the TrailMath app.Read-only access to your activities. Nothing is posted to Strava, and no training plan is created until you ask for one.

Distance (km)

Elevation gain (m)

Elevation loss (m)

Same as gain. Edit if different.

Finish time

Hours, or h:mm

3. Your predicted finish

153.0 km-effort (ITRA, gain only)174.4 km-effort

Add a past race or your index to get a finish time.

Istria 110K finish times by UTMB Index

Predicted finish on the Istria 110K course (111.0 km, 4,200 m D+) for each UTMB Index, with the margin to the 28h00 cutoff.

Istria 110K: predicted finish time by UTMB Index
UTMB Index	Predicted finish	Average pace	Margin to cutoff
850	10h22	5:36 /km	+17h38
800	11h19	6:07 /km	+16h41
750	12h23	6:41 /km	+15h37
700competitive	13h32	7:19 /km	+14h28
650	14h47	8:00 /km	+13h13
600	16h10	8:44 /km	+11h50
550	17h40	9:33 /km	+10h20
500mid-pack	19h19	10:26 /km	+8h41
450	21h07	11:25 /km	+6h53
400back of the pack	23h05	12:29 /km	+4h55
350	25h14	13:38 /km	+2h46
300	27h35	14:54 /km	+0h25

The 28h00 cutoff sits at about Index 291. The typical winning time, 9h27, sits at about Index 901. At the 2026 edition, the median of the 411 finishers took 18h30, about Index 524. A model estimate, not an official ITRA or UTMB figure.

From a result you already have

What the predictor gives on Istria 110K for a few common reference results.

Istria 110K: predicted finish from reference results
Road marathon	3h00 → 17h03	3h30 → 19h53	4h00 → 22h44	4h30 → 25h34
50 km trail, 2,000 m D+	5h30 → 14h15	6h30 → 16h51	7h30 → 19h25	8h30 → 22h00

Road marathons use the tool's rougher power-law fallback.

For arrival times at each checkpoint, use the Istria 110K aid station planner.

Istria 110K course in numbers

Climbing per km: 38 m
ITRA km-effort: 153 (100K)
Highest point: 1,017 m
Biggest climb: +639 m over 10.4 km at 5.8%
Steepest climb: +389 m over 2.8 km at 13.6%
Longest descent: -264 m over 13.4 km at 1.6% (Buje to Umag (Finish))
Track climbing above 3%: 33%
Winning time / cutoff: 9h27 / 28h00 (3x the winner's time)

Section-by-section climbs, descents and grades are on the Istria 110K course page.

Predict your Istria 110K finish time from a reference race result, adjusted for the course's 111 km and roughly 4,200 m of elevation gain. The overall cutoff is 28h.

About Istria 100 by UTMB - 110K

Istria 100 by UTMB - 110K covers 111 km with around 4,200 m of elevation gain, starting in Buzet, Croatia. The overall cutoff is 28 hours.

Crew access is allowed at Buzet (41.93 km) and Livade (74.14 km). Drop bags are available at Buzet.

Checkpoint data approximate - verify against the current official race guide at istria.utmb.world before your race.

How the prediction works

Your result becomes a UTMB Index, mapped onto Istria 110K by the calibrated model behind the ITRA / UTMB Index Estimator. Full methodology.

Build a training plan targeted at your Istria 110K goal time

TrailMath uses these models to build periodized plans adjusted to your goals and terrain.

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