Weight Loss Timeline Calculator

Explore an estimated weight loss timeline using a dynamic model of body composition, energy expenditure, and fluid changes. Individual results can differ.

Enter Your Information

Current Weight (kg)

Target Weight (kg)

Height (cm)

Age (years)

Planned Daily Intake (kcal/day)

1,000 kcal is a calculator limit, not a recommended or safe intake for everyone.

Known Maintenance Intake (optional, kcal/day)

Your average intake while weight was stable over several weeks. Leave blank to estimate from resting energy and activity.

Measured Body Fat (optional, %)

Leave blank to estimate from age, sex, and BMI. Body composition measurements also have uncertainty.

Sex used by the energy equation

Activity Level

Activity categories are approximate. A known maintenance intake overrides this estimate.

Include the Hall model's adaptive thermogenesisUses the published response to intake changes. Uncheck to compare a scenario without this response; individual adaptation varies.

How this estimate works

The Hall adult dynamic model tracks fat, lean tissue, glycogen, fluid, and changing energy expenditure. It replaces the fixed 7,700 kcal/kg rule and an arbitrary metabolic slowdown.

It assumes sustained calorie intake and unchanged activity, with 50% of calories from carbohydrates. Baseline sodium is modeled at 4,000 mg/day and scales with calories; this is a modeling assumption, not a dietary recommendation. Early scale changes include water.

These projections are for adults and are not calorie prescriptions. The model does not simulate pregnancy, breastfeeding, medication, surgery, or illness. Resting energy and activity estimates can differ from your actual requirements.

Research reviewed through 26 September 2026. Recent studies reinforce individual variability; they do not establish a universal metabolic slowdown.