An educational estimate — not medical advice.

Not professional advice

The information and estimates on this site are provided for general educational purposes only. They are not medical, nutritional, weight-management, fitness, or psychological advice, are not a diagnosis or treatment, and don't create any professional or advisory relationship. Changes to how you eat and train have real health consequences — before you act, especially before dropping to a low intake, talk to a doctor or a registered dietitian.

Estimates, not measurements

The calculator produces a directional estimate, not a measurement of your metabolism or a guarantee of any result. In particular:

• Resting metabolism is estimated with the Mifflin-St Jeor equation, which was validated against indirect calorimetry but still carries person-to-person variation. Your true RMR may differ.
• Metabolic adaptation (adaptive thermogenesis) is folded in as a conservative, disclosed estimate — not a measured personal constant. Real adaptation varies widely between people.
• The stall date and weight are where the model expects loss to slow to a crawl, not a hard stop or a clinical prediction. Treat them as a rough horizon, not a deadline.
• The safe-intake floor (~1,200 cal/day women, ~1,500 cal/day men) is a conservative general guardrail drawn from public guidance, not a medical threshold tailored to you. Some people need more; a professional can tell you what's right for your body.

Out of the model's lane

This tool does not account for GLP-1 medications, thyroid conditions, PCOS, other medical conditions, pregnancy, or medications, any of which can change the picture substantially. It is not designed for anyone under 18. If you are, or have been, affected by disordered eating, please treat any calorie target with care and speak with a qualified professional first — this tool is not a place to chase the lowest possible intake.

Verify before you rely on it

For guidance tailored to you, consult a doctor or a registered dietitian, and see reputable references such as the NIH Body Weight Planner and its methodology. We do our best to keep the model defensible and to cite primary sources, but we make no warranty of accuracy or completeness and accept no liability for decisions made based on this site. See our terms of use.

No affiliation

whenwilliplateau.com is an independent tool operated by Red Goggles LLC. It is not affiliated with, endorsed by, or connected to the NIH, NIDDK, any medical or nutrition organization, or any diet, supplement, or fitness brand.

Last updated: June 4, 2026