Hardrock 100 Cutoff Calculator
Hardrock 100 is the hardest 100-mile race in the world by reputation — 165 km with over 10,000 m of vertical, averaging 11,000 ft of elevation. This calculator projects your ETA at all 15 aid stations and the 7 enforced cutoffs.
What the GPX doesn't tell you.
10,000+ m of vertical gain — Hardrock crosses 13 mountain passes and peaks at Handies Peak (14,045 ft).
Altitude. Most aid stations are above 10,000 ft. Sea-level fitness does not transfer one-to-one up here.
Two nights of running. Even fast finishers cross into Saturday night, then Sunday morning. Sleep deprivation compounds altitude.
Hardrock has fewer enforced cutoffs than most 100-milers (7 enforced + finish out of 15 stations), but the cutoffs themselves are tight because the terrain is unforgiving. Direction alternates yearly — the data here is counter-clockwise. The Ouray cutoff (km 94, 27h) is often the make-or-break point: if you arrive there with less than an hour of buffer, the steep climb to Kroger's at 13,000 ft will catch you.
Where the race is decided.
Animas Forks (km 72) to Ouray (km 94) — the descent into Ouray is brutal on quads, and the subsequent climb to Kroger's at the highest aid station of the course will determine whether you finish.
Tactical advice for Hardrock 100.
Altitude-acclimatize for a week before the race. There is no substitute. The model cannot predict your altitude tolerance from a sea-level race result.
Aim for the Telluride cutoff (km 120, 34h) with at least 90 minutes of buffer. The final 45 km includes Putnam climb and a steep descent into Silverton.
Sleep early if you can — even 20 minutes at Ouray pays back later. Most DNFs in Hardrock are from collapse, not cutoffs.
More from RunPact.
- Ultra race time predictor — upload any GPX, get a course-aware finish time prediction.
- Custom cutoff calculator — for any race not in our featured list.
- Training plans — phase-based plans tailored to your race and current fitness.