This free GLP-1 weight loss calculator projects how much weight you might lose on Ozempic, Wegovy, Zepbound, or Mounjaro, based on average results from the major clinical trials. Enter your current weight, pick your medication, and see your projected timeline — then keep reading below for what the numbers mean and why individual results vary.
How This GLP-1 Weight Loss Calculator Works
The projections come straight from the pivotal clinical trials: the STEP 1 trial of semaglutide 2.4 mg (Wegovy), where participants lost an average of 14.9% of body weight over 68 weeks, and the SURMOUNT-1 trial of tirzepatide (Zepbound/Mounjaro), where the 10 mg and 15 mg doses averaged 19.5% and 20.9% over 72 weeks. The calculator interpolates the published week-by-week curves, so the shape of your projection — faster loss early, flattening later — matches what trial participants actually experienced. Ozempic projections use typical results at diabetes doses, which are meaningfully lower than Wegovy’s weight-loss dose.
The calculator also covers the Wegovy pill (oral semaglutide 25 mg, which averaged 13.6% over 64 weeks in the OASIS 4 trial), Saxenda (liraglutide 3 mg, about 8% over 56 weeks in the SCALE trial), and typical diabetes-dose results for Rybelsus — so daily-pill and daily-injection users can see realistic curves too. Using compounded semaglutide or tirzepatide? Pick the compounded option — it applies the branded trial curve for the same active ingredient, since compounds don’t have large trials of their own.
Why Your Results May Differ
A GLP-1 weight loss calculator can only show averages — and the range around those averages is wide. The biggest factors that move individual results:
- Dose and titration speed. Trial participants escalated to full dose on a fixed schedule; many real-world users stay at lower doses longer.
- Consistency. Missed doses flatten the curve more than most people expect.
- Type 2 diabetes. Average weight loss runs a few points lower in people with T2D across trials.
- Protein and strength training. They don’t just protect you from muscle loss — preserving lean mass keeps your metabolism higher through the flattening phase.
- Plateaus are built in. Notice both curves level off — that’s normal biology, not failure. Our GLP-1 plateau guide covers what to do when it happens.
GLP-1 Weight Loss Calculator FAQ
How accurate is a GLP-1 weight loss calculator?
It’s as accurate as averages can be. The numbers come from randomized controlled trials with thousands of participants, but your result depends on dose, consistency, diet, and biology. Think of the projection as a reference line to compare your real trend against — not a promise.
How much weight will I lose on Ozempic vs. Wegovy vs. Zepbound?
Trial averages: roughly 6% of body weight on Ozempic at diabetes doses, about 15% on Wegovy (semaglutide 2.4 mg), and about 19–21% on Zepbound or Mounjaro (tirzepatide 10–15 mg) — over 68–72 weeks in each case.
What if I’m losing slower than the calculator projects?
That’s common and usually not alarming — especially during dose titration. Clinicians often look at your response around week 12 as an early signal. If your trend stays flat for a month or more at a stable dose, bring your logged data to your prescriber and read our plateau guide for the usual fixes.
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This calculator and article are for educational purposes only and are not medical advice. Always consult your healthcare provider about your treatment and expectations.