ARC guide
How Long Does Fat Loss Take?
Use a week range, not a deadline. ARC plans fat-loss time from a percentage of each week's bodyweight.
Direct answer
Fat loss time is a range, not a date. ARC estimates it by applying 0.5%, 0.75%, or 1.0% of that week's bodyweight — then recalculating the next week from the new weight. Faster rates finish sooner; they are also harder to hold.
Key takeaway
Ask for a window, not a promise. If someone gives you an exact goal date from a single weekly pound target, they are oversimplifying the math.
Why a constant weekly number drifts
A common shortcut is “lose 1–2 lb every week until you arrive.” That treats the starting weight as if it never changes. As bodyweight drops, the same percentage of weight is a smaller number of pounds.
ARC’s timeline tool does not subtract the same amount forever. Each week’s projected loss is a percentage of that week’s projected weight. The series slows slightly as you get lighter. That is why the output is a week range, not a single day.
The three planning rates
The planner uses 0.5%, 0.75%, and 1.0% of bodyweight per week. Those are planning rates, not a guarantee of what your body will do. They exist so you can see a conservative window and a faster window on the same inputs.
The 1.0% end is the upper rate this product will project. It is not a target to beat. If the faster date still feels tight, use the slower rate or change the goal weight.
A worked example
Someone at 200 lb with a 180 lb goal is asking to lose 20 lb. At 1.0% of each week’s weight, the first week is about 2.0 lb; later weeks are less. At 0.5%, the first week is about 1.0 lb. The tool reports both week counts and both estimated dates, labeled as estimates.
Common mistake
Treating the earliest date as a deadline, then crashing calories when the scale is slower. The range is the product. If you are outside it, the next check is adherence, sleep, and whether the goal weight still makes sense — not a crash diet.
Use the ARC tool
Run the numbers instead of guessing from the article alone.
How ARC treats this
- ARC uses percentage-of-bodyweight planning rates as a product convention so projections stay proportional as weight changes.
- The calculator does not promise biological outcomes. Results are labeled as estimates.