Weight-change calculator

What this calculator actually measures

A percentage expresses a change relative to the starting number. If you select a five-percent scenario, the tool multiplies your starting weight by 0.05. It then subtracts that amount to show a hypothetical remaining weight. It does not estimate fat mass, muscle loss, changes in fluid, or future health outcomes.

The percentage is yours to explore; the calculator does not recommend it. A larger number is not automatically a better or safer goal. The appropriate direction, amount and pace of weight change depend on a person's health and circumstances.

Why there is no medication prediction

Response varies across individuals. A clinical trial describes the participants, product, doses, support and follow-up included in that study. A group average is not a reliable forecast for one person. This tool therefore does not label a percentage as your expected result from semaglutide, tirzepatide or another medicine.

Compounded products are not FDA-approved, and FDA does not review them for safety, effectiveness or quality before marketing. Data from an approved finished product must not be presented as proof of the outcome of a compounded preparation. [8]

How to discuss a realistic goal

CDC notes that even modest weight loss can improve some health measures for people with overweight or obesity. That does not mean everyone should lose weight, or that the same target applies to everyone. Medical history, nutrition, activity, sleep, side effects and long-term support all belong in the conversation. [5]

Ask your clinician which health measures matter for you, how progress should be assessed, whether a medication is appropriate, and when a plan should be reconsidered. A screening result such as BMI cannot answer those questions by itself. [4]

Interpreting the inputs and result

Use one weight unit throughout. The arithmetic is identical in pounds and kilograms; changing the unit selector does not automatically convert a number already entered, so re-enter the appropriate value. Percentages are restricted to 1–30 for this illustration, not because that range is a medically recommended target. Weight input limits are interface safeguards, not eligibility criteria.

The result is rounded to one decimal for readability. Short-term scale changes may include fluid and other factors, so avoid using one measurement as evidence that treatment is working or failing. No timeline is generated. Do not alter medication, food intake or hydration on the basis of the output.

Explore the adult BMI tool, plan a budget using your own quote, or read how prescription weight-management approaches differ.