Goal Date Calculator
How many weeks a weight goal takes at a steady rate, the date that lands on, and the daily calorie difference behind it.
At exactly this rate, the arithmetic reaches your goal on
Change
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Time
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Daily difference
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This is a calculator, not medical advice. It works only on the numbers you type in. What suits you personally depends on things this page knows nothing about — your health, your medication, your history — and a doctor or registered dietitian is the right source for that. The date is a division, not a prediction — real weight change is not linear.
The rate is the part you control
A date is only as good as the daily eating under it. Food Cal AI logs a meal from a photo or a description, keeps the running total against your target, and shows the trend over weeks rather than the noise of one morning.
What the date actually is
It is one division dressed up as a calendar. The change you want, divided by the rate you typed, gives a number of weeks; the weeks are added to today. Nothing about it knows anything about you, and it is right only for as long as the rate holds exactly — which it will not.
The daily calorie figure comes from the same arithmetic in the other direction. A kilogram of body fat stores roughly 7,700 calories, so half a kilogram a week is about 3,850 calories spread over seven days, or 550 a day. That is the number the rate is really asking for.
Why the real curve is not a straight line
- The first week is faster. Cutting carbohydrate lowers glycogen, and glycogen holds water. Two or three kilograms in week one is mostly that, and it does not repeat.
- The rate slows as you get lighter. A smaller body uses less energy, so an unchanged diet produces a shrinking deficit. The date at the top assumes this away.
- Plateaus are ordinary. Two or three weeks with no movement on the scale while everything else is unchanged is common, and normally resolves without anything being altered.
- The scale measures more than fat. Salt, hormonal cycles, when you last ate and when you last trained can each move it a kilogram in a day, in either direction.
Which is why a weekly average beats a daily reading
A single morning's weight is mostly noise. The signal is the trend over two to four weeks, and the practical version of that is weighing under the same conditions — same time, same state — and comparing this week's average against last week's, rather than today against yesterday.
Doing it that way also changes what a bad week means. Against a daily number, a kilogram up on Tuesday looks like failure; against a four-week average it is invisible, because it was never a real change to begin with.
Using the date well
Treat it as a sanity check rather than a deadline. It is genuinely useful for noticing that a goal implies eight months rather than the six weeks you had in mind, or that a rate you picked casually implies a deficit you would find hard to hold. It is not useful as a promise, and a date you miss is not evidence of anything except that the assumption of a constant rate was always false.
Questions
Where does 7,700 calories per kilogram come from?
It is the standard planning figure for the energy stored in a kilogram of body fat — about 3,500 calories per pound. It is an approximation, and a slightly generous one: it treats every kilogram lost as pure fat, when some of it is water and some is lean tissue. Useful for setting a starting deficit, not precise enough to explain a single week on the scales.
Why does the real thing never match the date?
Because the arithmetic assumes a constant rate and bodies do not provide one. Energy needs fall as body weight does, so the same food that produced a deficit in month one produces a smaller one in month four. Water shifts, glycogen, salt and hormonal cycles move the scale by a kilogram or two in either direction independently of fat. The first week is usually faster than the rest, and long plateaus are ordinary rather than a sign anything has gone wrong.
What is a reasonable weekly rate?
The usual guidance is somewhere around 0.5 to 1% of body weight per week, which for most people lands between a quarter and one kilogram. Above that, a larger share of what comes off tends to be muscle and water rather than fat, and the deficit needed gets hard to hold without being hungry enough to quit. Where you should sit inside that range depends on your health and circumstances, which is a conversation for a doctor or dietitian rather than a web page.
Does it work for gaining weight?
Yes. Set the goal above the current weight and the same division runs the other way, with the daily figure shown as a surplus. The same caveat applies in reverse: a bigger surplus does not build muscle proportionally faster, it mostly adds fat alongside it.
Should I be aiming for a goal weight at all?
Not necessarily. A single number on a scale says nothing about body composition, fitness or health, and for plenty of people a behaviour target — a training routine, a way of eating they can sustain — is more useful than a weight. If a goal weight is something you feel anxious or compelled about rather than curious, that is worth taking seriously and worth raising with a doctor; disordered eating is common and treatable, and a calculator is the wrong tool for it.
