Weight loss timeline

How is it calculated?

The base constant: a kilogram of body weight is roughly 7,700 calories. Losing half a kilo a week means a deficit of 550 calories a day. So far, so ordinary. Every calculator does this much.

The divergence starts after that. Your basal rate depends on your weight — in the Mifflin-St Jeor equation each kilogram carries 10 calories a day — so losing 5 kilos drops your maintenance level by about 78 calories. Keep eating the same plate and your deficit narrows on its own.

Scenario one — fixed calories: you find today's target and never change it. Each week your maintenance level is recalculated for your new weight, and the gap between the two produces that week's loss. The loss slows progressively and in theory stops at an EQUILIBRIUM WEIGHT: the point where your intake equals your maintenance.

Scenario two — fixed pace: you want to hold the weekly rate you picked. That requires rewriting your daily calories every week. It's why the calorie column in the table steps down; that column, not the date, is the real output.

Both scenarios respect the safety floor: no target below 1,200 calories for women or 1,500 for men is shown. When the floor is hit, the achievable deficit in scenario two narrows and the date slides back on its own — the calculation won't produce a plan you can't follow.

If your goal sits beyond the equilibrium weight, the timeline says so outright. Producing a date there is mathematically possible but meaningless in practice — and printing one with no warning is exactly what competing calculators do.

How to read your result

Where the two curves separate tells you how fragile your plan is. If the gap is small — a few weeks — the choice of scenario hardly matters. If it's large, never adjusting your calories will cost you months. The gap grows with the amount of weight to lose.

The slowdown isn't a failure, it's arithmetic. Most people who've held their plan for eight weeks and see the scale slow read it as "my metabolism is broken." Nothing is broken. A lighter body spends less energy, so the same plate now produces a smaller deficit, and that leaves three things you can do: lower the calories, raise the activity, or accept the slower pace as it is.

Read the table as an expectation chart, not a prescription. Real weight curves aren't this smooth: water retention, salt, carbohydrate intake and the menstrual cycle can swing the scale by a couple of kilos. A ten-day stall isn't a deviation from the plan, it's inside the noise. Look at the weekly average.

When picking a weekly rate, keep this in mind: the faster you go, the more of the loss comes from muscle. Above 1 kilo a week means meaningful muscle loss for someone who doesn't lift and keeps protein low, so if reaching the goal two weeks early costs you a lighter but weaker body and a lower metabolism on the day you arrive, it's plainly a bad trade.

If you got the unreachable warning, don't make cutting calories further your first move. Raising your activity level by one step lifts your maintenance, which lets you produce the same deficit at a higher intake — easier to sustain and better for preserving muscle.