Tirzepatide Weight Loss Calculator
Estimate your results by dose and starting weight
Use SURMOUNT trial averages to estimate your weight loss on tirzepatide (Mounjaro/Zepbound) — by maintenance dose, over time, and roughly how many pounds that is for your starting weight. These are population averages, not a promise; your own result depends on dose, diet, activity, and individual response.
How to estimate your tirzepatide weight loss
Tirzepatide produces some of the largest average weight loss of any approved medication, and the higher your maintenance dose, the more you tend to lose. Most of the loss comes over the first 9–18 months as you titrate up and your body responds.
In SURMOUNT-1 (72 weeks), the 5 mg dose averaged about 15%, 10 mg about 19.5%, and 15 mg about 20–22.5%. To estimate your pounds lost, multiply your starting weight by the percentage for your dose.
Average weight loss by maintenance dose (SURMOUNT-1, 72 weeks)
| Maintenance dose | Mean total weight loss |
|---|---|
| 5 mg | ~15%Best |
| 10 mg | ~19.5% |
| 15 mg | ~20–22.5% |
Typical timeline (toward a 15-mg result)
| Time on treatment | Typical total weight loss |
|---|---|
| Month 1 | ~3–4%Best |
| Month 3 | ~7–9% |
| Month 6 | ~12–15% |
| Month 12 | ~18–21% |
| 72 weeks | up to ~22.5% |
Estimated pounds lost by starting weight
| Starting weight | At 15% (≈5 mg) | At 20% (≈10–15 mg) |
|---|---|---|
| 150 lb | 23 lb → 127 lb | 30 lb → 120 lbBest |
| 180 lb | 27 lb → 153 lb | 36 lb → 144 lb |
| 200 lb | 30 lb → 170 lb | 40 lb → 160 lb |
| 250 lb | 38 lb → 212 lb | 50 lb → 200 lb |
| 300 lb | 45 lb → 255 lb | 60 lb → 240 lb |
What changes your result — and safety
Your maintenance dose is the biggest lever, followed by how long you stay on treatment, diet quality and protein, activity and resistance training, sleep, and individual biology. Reaching and holding 10–15 mg, paired with lifestyle changes, tends to land at the upper end.
These are estimates from trial averages, not medical advice or a guarantee. Your prescriber sets your dose and plan. Track your actual weekly weight in Shotlee to see your real curve instead of an average.
Frequently Asked Questions
In SURMOUNT-1, average total weight loss was about 15% at 5 mg, 19.5% at 10 mg, and 20–22.5% at 15 mg over 72 weeks. For your pounds, multiply your starting weight by that percent — e.g. 250 lb × 20% = 50 lb. Individual results vary.
Expect a few percent in the first month, ~7–9% by month 3, and the bulk of the loss over 9–18 months as you titrate up. Higher maintenance doses keep the loss going longer.
On average yes — tirzepatide’s ~20–22.5% at 15 mg exceeds semaglutide’s ~15% at 2.4 mg in their respective trials, though they were not tested head-to-head in those obesity studies. Individual response still varies.
Roughly 15% at 5 mg, 19.5% at 10 mg, and 20–22.5% at 15 mg in SURMOUNT-1. Higher maintenance doses generally mean more weight loss, balanced against tolerability.
Yes. Shotlee logs your weekly weight, dose, and side effects and charts your actual trend — free.
Track Your Real Tirzepatide Curve in Shotlee
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