Triathlon Run Pace Calculator
Calculate your triathlon run pace.
Convert run time to pace per km or mile and predict finish time for Sprint, Olympic, or Ironman run legs.
The run is the final discipline in triathlon — done on tired legs after swimming and cycling. Run pace in triathlon is typically 15–45 seconds per km slower than a standalone running race of the same distance, due to accumulated fatigue.
Standard triathlon run distances:
- Sprint: 5 km
- Olympic: 10 km
- Half Ironman (70.3): 21.1 km
- Ironman: 42.2 km (full marathon)
Pace formula: Pace per km = total run time (seconds) / distance (km)
Worked example: Olympic run (10 km) in 52 minutes (3,120 seconds): Pace = 3,120 / 10 = 312 seconds = 5:12 per km
Estimating your triathlon run pace: A common formula: triathlon run pace = standalone race pace × 1.05 to 1.15 (5–15% slower)
If your 10 km standalone PB is 48 minutes (4:48/km), expect 50–55 minutes in triathlon.
Pacing strategy: Run the first kilometer conservatively — it takes 800–1,500 m for the legs to transition from cycling. Going out too hard results in a much slower second half. Even pacing or negative splits produce the fastest overall run time.
Ironman run: In a full Ironman, heart rate control is critical. Most athletes run at 65–75% of max heart rate to avoid burning out before kilometer 30.