Why percentage, not pounds
The pounds you lose depend on where you started; the percentage of your body weight doesn't, which is why it's the measure clinicians and researchers use to compare results fairly. Losing 20 lb means something very different at 300 lb than at 150 lb, but a 7% loss means the same thing for both.
How do you calculate weight loss percentage?
Weight loss % = (starting weight − current weight) ÷ starting weight × 100. For example, dropping from 200 lb to 186 lb is a 7% loss. The calculator above does the math for you, and if you add a goal, it shows how far along you are.
What counts as a meaningful weight loss?
Because percentage is the yardstick the evidence uses, it makes clinical results easy to compare against: the major GLP-1 medication trials report average losses of about 15% with semaglutide [1] and up to roughly 20% with tirzepatide [2]. Seeing your own number in the same terms puts those benchmarks in context.
A percentage is a scoreboard, not a verdict. Weight is one signal among many, and how you feel, move, and function matters at least as much. And if your number has you weighing whether a medication like a GLP-1 could help, that's a conversation to have with a clinician.
References
[1] Wilding JPH, Batterham RL, Calanna S, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021;384(11):989-1002. doi:10.1056/nejmoa2032183 https://pubmed.ncbi.nlm.nih.gov/33567185/
[2] Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022;387(3):205-216. doi:10.1056/nejmoa2206038 https://pubmed.ncbi.nlm.nih.gov/35658024/