Free calculator

GLP-1 Weight-Loss Calculator

Enter your current weight and a medication to see an illustrative estimate based on average results from the clinical trials. It's a guide, not a prediction — real results vary a lot.

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How this estimate works

The figures here come from the average total body-weight reductions reported in the major clinical trials, alongside lifestyle changes: roughly 15% for semaglutide 2.4 mg (Wegovy), about 20% at higher doses of tirzepatide (Zepbound), and around 5–8% for liraglutide 3.0 mg (Saxenda). The calculator applies the average and a typical range to your weight.

Why your result will differ

These are averages over roughly 16–18 months at full doses. Individual results vary widely — some people lose more, a minority respond poorly, and your dose, starting weight, and habits all matter. Treat this as an illustration to set expectations, not a promise. Our weight-loss guide covers the realistic month-by-month picture, plateaus, and protecting muscle.

Frequently asked questions

How much weight can you lose on a GLP-1?

On average in trials: about 15% for semaglutide (Wegovy), roughly 20% at higher tirzepatide (Zepbound) doses, and about 5–8% for liraglutide (Saxenda). Averages — individuals vary widely.

Is this calculator a guarantee of results?

No. It applies clinical-trial averages to illustrate a typical range — it is not a prediction, and can't account for your dose, health or habits.

Sources & further reading

  1. STEP trials (semaglutide 2.4 mg) — average ~15% body-weight reduction at 68 weeks.
  2. SURMOUNT trials (tirzepatide) — average ~15–21% reduction across doses.
  3. SCALE trials (liraglutide 3.0 mg) — average ~5–8% reduction.
Educational estimate, not medical advice. This calculator gives a general estimate from standard public formulas and does not diagnose, treat, or recommend any medication or dose. Results vary by individual. Always talk to a qualified clinician about your own situation.