Running Tools

Free running tools including pace, splits, race prediction, VDOT, fueling, time goals, heart rate zones, hydration, and age grading.

• Pace Calculator — Free running pace calculator. Convert finish time and distance into average pace per kilometer.
• Race Time Predictor — Predict race finish times across distances using your latest race result and fatigue profile.
• Race Splits Calculator — Plan even or negative race splits and get checkpoint-by-checkpoint cumulative targets.
• Heart Rate Zones Calculator — Calculate personalized running heart rate zones using the Karvonen heart rate reserve method.
• Hydration & Sweat Rate Calculator — Estimate sweat rate and race hydration targets from pre/post run weight and fluid intake.
• Age Grading Calculator — Estimate age-graded running performance and compare your result across age groups.
• Training Pace Calculator — Free training pace calculator for runners. Get recovery, easy, long run, marathon pace, tempo, and interval pace zones from a recent race result.
• VDOT Calculator — Calculate VDOT from your race result and view equivalent predicted race times across 5K, 10K, half marathon, and marathon.
• Marathon Fueling Calculator — Plan marathon fueling with carbohydrate, hydration, and sodium targets based on race duration and sweat rate.
• Time Goal Calculator — Calculate goal finish time from target pace and distance, with cumulative split checkpoints for race execution.