Extended Fasting Weight Loss Calculator
A physiology-based model that estimates fat loss, glycogen depletion, protein breakdown, and total weight change during multi-day fasting. Adjust your inputs to see how your projected weight curve changes in real time. For educational purposes only - estimates are based on simplified physiological assumptions and individual results may vary. Fasting carries potential risks, so consult a healthcare professional before attempting extended fasting.
Your Starting Point
Enter your baseline stats.
Physiological Parameters
If you don’t know your Body Fat or Bone Mass, leave them blank and we’ll auto‑estimate.
Daily Activity
Fasting Protocol
Model Parameters
Share Your Feedback and Fasting Results
Tried the calculator or completed an extended fast yourself? Share your results, observations, or questions. Real-world experiences help improve this model and help others understand what to expect during multi-day fasting.