6 free tools
Running calculators
Pick a tool below. Each one runs instantly in your browser — no sign-up, nothing to install, and they're free forever.
AI Run Analysis
Upload a Garmin .fit run and get a friendly AI coach read of your pacing, heart-rate drift and effort.
Open- 01
Running Pace Calculator
Calculate your running pace per km and per mile from any distance and time. Free, instant pace and speed calculator.
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Race Time Predictor
Predict your race finish time for 5K, 10K, half and full marathon from a recent result using the Riegel formula.
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Splits Calculator
Get even per-km or per-mile splits for any goal finish time and race distance.
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Training Pace Zones Calculator
Calculate easy, marathon, threshold, interval and repetition training paces from your threshold pace.
Open - 05
Treadmill Pace Converter
Convert treadmill speed in mph or kph to running pace per km and per mile.
Open - 06
Age Grading Calculator
Calculate your WMA age-graded percentage and age-graded time for 5K, 10K, half marathon and marathon by age and sex.
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