Physics View of Weight Change
Weight change follows energy balance over time. Food adds chemical energy. Movement, digestion, and body maintenance spend energy. This calculator translates that idea into daily numbers. It estimates resting burn, activity burn, target intake, and projected timeline. The aim is not extreme restriction. The aim is a steady plan that can fit normal life.
Why Daily Energy Matters
Your body uses energy even at rest. That value is called basal metabolic rate. Height, weight, age, and sex affect it. Activity then raises the total daily need. A smaller intake than this need creates a deficit. A larger intake creates a surplus. The calculator also converts stored body energy into joules. This adds a physics based view of the goal.
Smart Planning
A useful plan should be realistic. Very low targets can reduce energy, hunger control, and adherence. This page therefore shows a practical calorie floor. It also compares the selected pace with the estimated time to goal. Users can test slower or faster changes. Small differences often matter. A few hundred calories each day can change the timeline by weeks.
Because the model is adjustable, it can support many scenarios. You can estimate maintenance, moderate loss, or a goal reset after progress stalls. The physics view helps explain why time matters. A small daily deficit becomes large over months, while a missed day usually has limited impact when the weekly pattern stays fairly consistent.
Habits Behind the Numbers
Calories are only one part of progress. Protein, steps, sleep, and meal consistency affect results. The calculator includes protein and step fields so the plan feels more complete. Protein supports lean mass. Steps add low stress movement. The habit score gives a simple review of the selected plan. It is not a medical score. It is a planning signal.
Using the Projection
The chart shows an estimated weight path. It assumes the same intake, activity, and pace continue. Real weight changes are less smooth. Water, sodium, training, stress, and hormones can shift scale weight. Use the chart as a guide, not a promise. Recheck inputs every few weeks. Update activity and weight to keep the estimate useful.