Made for the long run.

MyRunCalc is a free set of practical running tools. Calculate pace, plan race splits, convert speeds, explore Backyard Ultra distances, and estimate heart-rate zones without creating an account.

Precision before presentation

Distances are calculated in meters and times in seconds. We use 42.195 km for the marathon, 21.0975 km for the half marathon, and 1,609.344 meters for a mile. Calculations retain precision until results are displayed.

Clear sources, honest limits

Reference records are published only after authoritative verification. Heart-rate zones and pace targets are informational estimates, not a coaching plan or medical guidance.

These tools provide informational estimates, not personalized medical advice. Targets do not guarantee performance or safety. Consider your fitness, terrain, weather, altitude, and recovery. For health concerns, consult an appropriate healthcare professional.