Predict your 5K, 10K, Half Marathon, and Full Marathon finish times from any recent race result using Pete Riegel fatigue exponent formula.
Race Finish Time Predictor (Riegel Formula) is an accurate, instant, and private in-browser calculator created by VibeTool. It calculates standard physiological, lifestyle, and fitness formulas entirely within your browser memory. No inputs or figures are transmitted across the internet, ensuring 100% privacy and real-time computation.
Are my personal entries stored on a server?
No. All calculations run strictly in client-side JavaScript inside your browser. No personal health, schedule, or financial numbers are transmitted or stored remotely.
Are the formulas clinically and mathematically accurate?
Yes. Calculations use peer-reviewed standards such as the US Navy Body Fat equation, WHO risk metrics, Karvonen target heart rate zones, and standard metabolic constants.
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