| Lane | Calories/day | Opening pace | Finish by | Notes |
|---|---|---|---|---|
| {{ option.label }} | {{ format(option.calories) }} | {{ option.weeklyChangeText }} | {{ option.finishDateLabel }} | {{ option.note }} |
| Metric | Value |
|---|---|
| {{ metric.label }} | {{ metric.value }} |
| Stage | Date | Weight ({{ weightUnit }}) | {{ changeToDateHeader }} | BMI | TDEE | Cal target |
|---|---|---|---|---|---|---|
| {{ row.label }} | {{ row.dateLabel }} | {{ formatDec(row.weight) }} | {{ formatSigned(row.change) }} | {{ formatDec(row.bmi) }} | {{ format(row.tdee) }} | {{ format(row.cal) }} |
Weight-loss planning is easier when a goal is translated into a daily calorie target and a realistic pace of change. The key question is not only how much weight you want to lose, but how quickly that target can be approached without pushing the plan into an impractical deficit. This calculator turns age, sex, height, current weight, goal weight, timeframe, and activity level into a structured weekly projection instead of a single calorie number.
The package estimates basal metabolic rate and total daily energy expenditure, then works backward from the requested timeframe to derive a daily deficit or surplus. From there it builds a week-by-week schedule, warning flags, a metrics table, and three visual views: projected weight change, calorie trend, and a decision map that plots daily deficit against weekly pace.
A realistic use case is comparing whether the same goal should be approached over 8 weeks or 16 weeks. The shorter plan may produce a more dramatic daily deficit, more warnings, and a steeper weekly drop. The longer plan can show a gentler calorie target and a steadier trajectory even though the final goal is unchanged.
The tool also accounts for policy choices rather than hiding them. The advanced settings let you change the energy-per-kilogram assumption and choose whether a calorie floor should be ignored, applied by sex, or set manually. Those controls matter because an aggressive plan can look mathematically neat while still being impractical in real life.
The boundary is that this is a planning model, not a medical program. It does not know your medications, health conditions, body-composition changes, or adherence. It is best used to compare scenarios and spot obviously aggressive plans before you commit to them.
Start with a realistic timeframe. The package warns when the requested pace implies faster loss than common steady-progress guidance. That warning is useful because the same goal weight can produce very different day-to-day demands depending on whether you give it 6 weeks, 12 weeks, or several months.
The summary metrics are the right first stop: BMR, TDEE, daily deficit or surplus, and daily calorie target. If those look implausible, the charts and schedule will not fix the plan. The weight projection and calorie trend are then helpful for understanding how the same target plays out over time rather than as a static daily number.
The calorie floor policy is there to force a practical conversation. Safe-by-sex applies 1,200 kcal/day for female entries and 1,500 kcal/day for male entries, while custom lets you set your own minimum. If the floor is triggered, the package tells you so explicitly. That means the requested rate of change is no longer being followed exactly and should be interpreted as floor-limited instead.
The weekly schedule matters because calorie needs change as projected weight changes. The package recalculates BMR and TDEE across the timeline, so later weeks are not just copied from week 1. That makes the plan more useful than a flat “eat this many calories forever” estimate.
Treat the tool as a scenario comparator. It is most informative when you ask questions like “What happens if I extend the timeframe?” or “What if I set a safer floor?” rather than assuming the first target is the correct one.
The model starts with BMR from the Mifflin-St Jeor equation and scales it to TDEE using an activity multiplier selected in the form. The goal difference between current weight and target weight is then spread across the chosen timeframe, converted into a weekly change, and transformed into a daily energy deficit or surplus using the configured kilocalories-per-kilogram constant.
The package then calculates a daily calorie target by subtracting that deficit from TDEE. If a calorie-floor policy is active, the target is raised to the floor when the raw result would drop below it. This is one of the reasons the schedule can diverge from the originally requested pace: the floor is treated as a practical override rather than as a warning only.
The weekly schedule is recalculated iteratively. For each projected week, the tool computes the projected weight, recalculates BMR from that new weight, applies the activity factor again, and stores the resulting TDEE and calorie target. That is why the schedule can show a gradual drift in maintenance needs instead of repeating the same weekly TDEE indefinitely.
The warnings are explicit. Short timeframes, excessive weekly change beyond roughly 1 kg/week or 2 lb/week, non-positive calorie targets, and floor-limited outputs are all flagged. If the goal weight is above the current weight, the tool flips logically into a surplus-oriented plan instead of pretending the target is still weight loss.
| Input or control | Package behavior | Why it matters |
|---|---|---|
| Timeframe | Accepts weeks or months, with months converted using 4.345 weeks | Controls how aggressive the required weekly change becomes |
| Energy per kg | Defaults to 7,700 kcal/kg and can be customized | Changes how the weekly weight goal becomes a daily calorie gap |
| Calorie floor policy | Can be none, sex-based safe floor, or custom minimum | Keeps the target from dropping below a chosen practical threshold |
| Warnings | Flag aggressive pace, floor application, and other implausible states | Prevents false confidence in mathematically neat but impractical plans |
| Surface | What it shows | Exports available |
|---|---|---|
| Plan Metrics | BMR, TDEE, daily deficit or surplus, calorie target, timeframe, total and weekly change | CSV, DOCX, row copy |
| Weekly Schedule | Projected weight, change to date, week-specific TDEE, and daily target | CSV, DOCX, row copy |
| Charts | Weight projection, calorie trend, and weight-change map | PNG, WebP, JPEG, CSV |
| JSON | Inputs, warnings, summary metrics, and the weekly schedule array | Clipboard copy and JSON download |
The daily calorie target is the practical headline, but the warning list tells you how trustworthy that headline is. A floor-limited target means the plan could not fully support the requested pace without crossing the selected minimum. An aggressive weekly change warning means the target may be mathematically possible yet still difficult to follow sustainably.
The weekly schedule is also a realism check. If maintenance needs decline gradually across the plan, the tool is showing why the same calorie target can feel different later than it did in week 1. Use that trend to decide whether the timeframe still feels sensible.
A user tests the same goal weight over two different timeframes. The shorter version drives a larger daily deficit and may trigger warnings, while the longer version reduces the required daily restriction and often looks more sustainable.
A very aggressive target would mathematically require calories below the selected floor. The package raises the target to the minimum, shows a floor warning, and still lets the user inspect the resulting slower path rather than pretending the original pace is unchanged.
No. It estimates energy targets and projected weight change, not how fat, water, or lean mass will shift in practice.
Because the projected weight changes, which changes the recalculated BMR and TDEE values in later weeks.
The package switches logically into a surplus-oriented plan instead of treating the scenario as weight loss.