The arithmetic is easy. What it leaves out is the part worth reading, so this shows four rates rather than one.
Estimates are for general guidance only and are not medical advice. For a personalised plan, book a free guided tour at RPM Gym.
The headline is the size of the job: how many kilograms sit between where you are and where you want to be. Under it are four rows, one for each weekly rate, and they are the same subtraction divided four ways.
Four rather than one, deliberately. A single figure under a label like Estimated time reads as a forecast, and the division behind it is not forecasting anything — it is describing a plan that holds perfectly every week from now until the end. Showing the spread makes the choice visible: 10 kg is 40 weeks at a quarter-kilo a week and 10 weeks at a full one, and those are different years of your life, not different arithmetic.
The share-of-bodyweight row is the sanity check. Half a kilo a week is 0.57% of bodyweight at 88 kg and 0.71% at 70 kg — the same plan asks progressively more of you as you get lighter, which is a large part of why plans stall in month three rather than month one.
The check-in rows are the actual product. Four weeks is long enough for water, food volume and hormonal shifts to stop dominating the scale, and short enough that you can change something while it still matters. What you do at that point is compare the real trend against the row you picked — and then adjust the plan, not the target.
Gap = current weight − goal weight Weeks at a rate = gap ÷ that rate Share of bodyweight = rate ÷ current weight × 100 All four offered rates are shown, not just the one selected. There is no energy term anywhere in this page. No 7,700 kcal per kilogram, no 3,500 per pound, and no conversion between a deficit and a date.
Someone at 88 kg who wants to reach 78 kg, planning half a kilo a week.
Twenty weeks at the planned rate — and the row above and below it are the reason to read the whole table. The difference between the gentlest and the most aggressive plan here is thirty weeks, which is the real decision. What none of the four rows is, is a date: they are what the subtraction gives if nothing interrupts, and something always interrupts.
At the four rates this page offers: 40 weeks, 20 weeks, 13 weeks or 10 weeks. That spread is the honest answer, and the reason it is a spread rather than a number is that the arithmetic assumes a rate holding perfectly for the whole run. What actually determines your answer is which of those four you are still following in month four.
Because one estimate would be more confident than the arithmetic behind it. A single figure under Estimated time reads as a prediction, and this is a subtraction divided by a rate — it has no information about you beyond two weights. Four rows say what the tool actually knows, which is what each rate would buy if it held.
This page will not rule on that, because the right rate depends on your starting point, how much you have to lose, what you are training, and what you can sustain — none of which is in the two fields above. What the share-of-bodyweight row does tell you is that a fixed weekly rate asks more of you the lighter you get.
Because a lighter body costs less to run. The energy you spend falls as your weight falls, so the same eating pattern produces steadily less loss over time, and the arithmetic on this page cannot see that happening. It is why every row is most reliable at the start and least reliable at the end, and why the four-week review is worth more than the projection.
Not necessarily, and two weeks is usually too short to tell. Water, gut contents, salt, sleep and training all move scale weight by amounts comparable to a fortnight of real change. That is what the four-week checkpoint is for — long enough for the noise to average out, short enough to still act on.
The fields are in kilograms and the rates are kilograms per week, so convert before entering. What the page will not do is offer a pounds mode with a 3,500-calorie rule attached, because that rule has the same problem as the kilogram version — it treats a moving target as a constant.
The rate that works is the one you are still on in month four, and that has more to do with how a week is built than with willpower. If you would rather set that up with someone than guess at it, the guided tour at Al Manhal is free.