Question 1

How long will it realistically take me to lose weight?

Accepted Answer

It depends on your starting weight, goal, calorie deficit, and how consistently you follow your plan. HonestSlim's answer is always a range, not a single date — because real weight loss is variable. For a typical scenario of 10 kg to lose at a 500 kcal/day deficit with 80% adherence, most simulated outcomes land between 16 and 28 weeks.

Question 2

Why does this calculator show a range instead of a single date?

Accepted Answer

Because weight loss is not deterministic. Your adherence varies week to week. Water retention fluctuates by 1–2 kg. Your metabolism slows as you lose weight. A single-date calculator ignores all of this. HonestSlim runs 5,000 simulated journeys and shows you the actual probability distribution. The width of the fan is information, not noise.

Question 3

What does the fan chart actually show?

Accepted Answer

The fan chart shows five percentile lines from 5,000 simulated weight loss journeys. The best-case (10%) line shows the fastest 10% of outcomes. The slow (90%) line is the realistic outer limit. The median (50%) line divides the distribution in half. The 30 faint lines are individual simulated journeys with their own plateaus and rebounds.

Question 4

Why does lowering adherence change my results so much?

Accepted Answer

Adherence variation compounds over time. Consistent partial adherence — hitting 70% of your plan instead of 90% — meaningfully reduces your average weekly deficit and dramatically widens the variance of outcomes. The adherence slider lets you be honest with yourself before you start, not six months in when you're wondering why the original date came and went.

Question 5

How accurate is this weight loss probability calculator?

Accepted Answer

It is a statistical model, not a medical prediction. The Mifflin-St Jeor equation has roughly ±10% individual variance — real metabolisms differ. The model does not account for activity level, muscle gain from resistance training, medical conditions, or medications. Use the fan chart to understand the realistic range of outcomes, not to predict an exact week.