Training Calculators
Data-driven tools built from real training algorithms. The same calculations I use for my own marathon, Ironman, and HYROX preparation.
Race-Specific
Calculators designed for specific race formats
HYROX Pace Calculator
Division-Specific Pacing
Calculate running splits and station time targets for HYROX. Division-specific pacing with strength profile adjustments.
Try Calculator for FreePace & Prediction
Predict race times and calculate optimal pacing
Marathon Pace Calculator
Calculate splits and pacing strategy for any distance from 5K to ultramarathon.
Coming Soon Coming SoonRace Time Predictor
Predict finish times using Riegel formula, VDOT, and CTL-adjusted methods.
Coming Soon Coming SoonBoston Cutoff Tracker
Track your BQ buffer, see cutoff projections, and get age-up predictions.
Coming SoonTraining Zones
Calculate your training zones for structured training
Training Zones Calculator
Calculate HR, pace, and power zones using Karvonen, %Max HR, or LTHR. Compare Strava vs Garmin vs TrainingPeaks.
Try Calculator for FreeHeart Rate Zones
Calculate HR zones from max heart rate or lactate threshold heart rate.
Try Calculator for Free Coming SoonMarathon HR Pacer
Heart rate-based marathon pacing with terrain and weather adjustments.
Coming SoonReal Algorithms, Real Results
These calculators are ported from the training analysis system I built for my own marathon and Ironman preparation. They use the same algorithms used by professional coaches and sports scientists.