GLP-1 weight loss calculator
Enter your starting weight to see what the average results of the main semaglutide (Wegovy) and tirzepatide (Mounjaro, Zepbound) trials would mean for you, and add your current weight to see your own percentage lost.
Your progress
Add your current weight to see how much you've lost so far.
Trial averages for your starting weight
For a starting weight of 220.0 lb:
| Treatment | After | Average change | Average loss | Ending weight |
|---|---|---|---|---|
| Semaglutide 2.4 mg (Wegovy) | 68 weeks | −14.9% | 32.8 lb | 187.2 lb |
| Placebo (STEP 1) | 68 weeks | −2.4% | 5.3 lb | 214.7 lb |
| Tirzepatide 5 mg (Mounjaro, Zepbound) | 72 weeks | −15.0% | 33.0 lb | 187.0 lb |
| Tirzepatide 10 mg | 72 weeks | −19.5% | 42.9 lb | 177.1 lb |
| Tirzepatide 15 mg | 72 weeks | −20.9% | 46.0 lb | 174.0 lb |
| Placebo (SURMOUNT-1) | 72 weeks | −3.1% | 6.8 lb | 213.2 lb |
These are the average results in two large trials of adults without diabetes, alongside diet and exercise advice. Individual results vary widely, and this is not medical advice.
How to use it
- Pick kilograms or pounds and enter your weight before you started.
- Add your current weight to see how much you've lost, as a weight and as a percentage.
- Compare with the trial averages, remembering that they are averages: many people lose more or less.
What the trials found
In STEP 1, 1,961 adults with obesity or overweight and a related health condition, none with diabetes, took semaglutide 2.4 mg once a week or a placebo for 68 weeks, alongside a lifestyle programme. Average weight fell by 14.9% with semaglutide and 2.4% with placebo.
In SURMOUNT-1, 2,539 adults without diabetes, with an average starting weight of 104.8 kg (231 lb), took tirzepatide or a placebo for 72 weeks, including a 20-week period of dose increases. Average weight fell by 15.0% on 5 mg, 19.5% on 10 mg and 20.9% on 15 mg, against 3.1% on placebo.
Wegovy, Ozempic, Mounjaro and Zepbound
Wegovy and Ozempic both contain semaglutide. Wegovy is the 2.4 mg weekly dose used for weight management and studied in STEP 1; Ozempic is prescribed for type 2 diabetes at doses of up to 2 mg, so its results aren't the same as the figures above. Mounjaro and Zepbound both contain tirzepatide.
Brand names belong to their owners, and this tool isn't affiliated with them. Which medicine, which dose and how fast to increase it are decisions for you and your doctor.
How fast is healthy?
For weight loss through diet and exercise, the CDC notes that people who lose about 1 to 2 pounds (0.5 to 1 kg) a week are more likely to keep it off. On medication the pace is often faster at first and slows later; your prescriber will tell you what to expect.
Frequently asked questions
How much weight can you lose on Wegovy?
In the STEP 1 trial, adults without diabetes taking semaglutide 2.4 mg lost 14.9% of their body weight on average after 68 weeks, alongside diet and exercise advice. For someone starting at 220 lb that is about 33 lb, but individual results vary widely.
How much weight can you lose on Mounjaro?
In the SURMOUNT-1 trial, average weight loss after 72 weeks was 15.0% on tirzepatide 5 mg, 19.5% on 10 mg and 20.9% on 15 mg. For a starting weight of 220 lb that is roughly 33, 43 and 46 lb.
How much weight can you lose on Ozempic?
Ozempic is semaglutide prescribed for type 2 diabetes at doses of up to 2 mg. The 14.9% average comes from the 2.4 mg weight-management dose (Wegovy) in people without diabetes, so results on Ozempic can differ. Ask your doctor what to expect.
How do I calculate my weight loss percentage?
Subtract your current weight from your starting weight, divide by your starting weight and multiply by 100. Going from 220 lb to 200 lb, for example, is 20 ÷ 220 × 100 = 9.1%.
Is losing 5% of your body weight worth it?
Yes. The CDC notes that even a modest loss, such as 5% of your weight, can help improve blood pressure, cholesterol and blood sugar, which can lower the risk of some chronic diseases.
Is this calculator medical advice?
No. It shows averages from two clinical trials and simple arithmetic. Your own results depend on many things, and decisions about medicines and doses belong with your doctor.