Free tools
Training calculators for serious endurance athletes
Free, no-signup tools to compute the numbers that actually drive adaptation: pace targets, VDOT, heart-rate zones, FTP. Same formulas SportPlan uses inside the adaptation engine — exposed publicly so you can do the math yourself.
Pace calculator
Compute total time from distance + pace, or pace from distance + time. See splits at 1 km, mile, 5K, 10K, half-marathon, and marathon.
VDOT calculator
Get your Jack Daniels VDOT from any race result, plus Easy, Marathon, Threshold and Interval training paces, and predicted times at other race distances.
Heart-rate zones
5 training zones from age (Tanaka or Fox formula) or your tested max HR. Karvonen reserve method when you add resting HR.
FTP calculator
Compute FTP from a 20-minute test or a ramp test, plus the 7 Coggan power zones and your W/kg ratio.
Race time predictor
Predict your finish time at 5K, 10K, half marathon, marathon or 50K from a recent result. Riegel's formula with an adjustable fatigue exponent.
Want the calculators built into your training plan?
SportPlan auto-applies your VDOT, HR zones, and FTP to every session — and re-calibrates them after each field test. See your first week before you pay. €9.99/month, cancel anytime.
Methodology designed by Ramon Curto, MSc Exercise Physiology
Ramon Curto designed SportPlan's endurance-training methodology from exercise-physiology principles. SportPlan applies it autonomously to the information you enter and the data you choose to connect; it is not ongoing one-to-one coaching or medical care.
Last revised July 2026
- MSc Exercise Physiology
- Endurance-training methodology
- Connected training-data analysis
- Block periodization · Polarized training