Free tools for triathletes and endurance athletes. No sign-up required. Want all of these automated against your actual training data? Connect your apps →
Pace Converter
Convert between pace and speed units for swim, bike, and run.
Race Time Predictor
Predict marathon, half, and 10K times from a recent race result.
Triathlon Split Calculator
Target swim, bike, and run splits for Sprint to Ironman.
Running Zone Calculator
VDOT training paces from a recent 5K, 10K, half, or marathon time.
FTP Calculator
Estimate Functional Threshold Power and cycling power zones.
Swim CSS Calculator
Critical Swim Speed and swim zones from time trials.
TSS Calculator
Training Stress Score for cycling, running, and swimming.
Weekly Volume Planner
Week-by-week triathlon plan with automatic periodization.
Brick Workout Generator
Bike-to-run brick workouts tailored to race distance.