How much weight will I lose on tirzepatide or semaglutide?

In their main trials, average weight change was about -15% to -21% for tirzepatide (SURMOUNT-1, 72 weeks) and -14.9% for semaglutide 2.4 mg (STEP 1, 68 weeks). Individual results vary widely; this calculator shows the trial average applied to your weight.

Is this calculator a prediction?

No. It applies the average result from each medication's main trial to your starting weight. Many people lose more or less than the average.

Tools / Weight loss calculator

Weight loss medication calculator

See what the average person lost in each medication's main trial, applied to your weight. It's an average, not a prediction.

1 Your weight

Add your height for BMI (optional)

2 Medication

3 Dose studied

Enter your weight to see results.

Every option, for your weight

Average loss in each trial at each dose studied. Click a row to select it.

How to read this

These are averages from each medication's main placebo-controlled trial, applied to your starting weight. Trials lasted 56 to 72 weeks, enrolled adults with a BMI of 30 or more (or 27 or more with a weight-related condition), and most were funded by the manufacturer. Weight tends to come back after stopping. Trials differ, so compare rows with care; see the full comparison for head-to-head results. Liraglutide's trial reported kilograms, so its percentage is calculated from the average loss and average starting weight. Educational only, not medical advice: talk to a clinician about whether any medication is right for you.