Enter your height and weight to see how much you could lose with a gastric sleeve at 1, 3, 6, 12 and 18 months, then compare it with any other procedure. Based on published %EWL data, reviewed by Dr. Alejandro López, board-certified bariatric surgeon.
After a gastric sleeve (vertical sleeve gastrectomy, VSG) most patients lose 60–70% of their excess weight in the first 12 months and 65–75% by 18 months. Excess weight is your current weight minus your ideal weight at a BMI of 25. The table shows the typical %EWL at each milestone and what it means in pounds for three example patients.
Ideal weight = 25 × height² · Excess weight = current weight − ideal weight · Expected loss = excess weight × %EWL
Example: at 5′6″ and 260 lb your ideal weight is about 155 lb and your excess weight about 105 lb, so 60–70% EWL means 63–74 lb lost in the first year.
Want to understand what each stage feels like? Read our gastric sleeve weight loss timeline.
| Milestone | %EWL | 5′4″ · 220 lb (74 lb excess) | 5′6″ · 260 lb (105 lb excess) | 5′8″ · 300 lb (136 lb excess) |
|---|---|---|---|---|
| 1 month | 10–15% | 7–11 lb | 11–16 lb | 14–20 lb |
| 3 months | 25–35% | 19–26 lb | 26–37 lb | 34–48 lb |
| 6 months | 45–55% | 33–41 lb | 47–58 lb | 61–75 lb |
| 12 months | 60–70% | 44–52 lb | 63–74 lb | 82–95 lb |
| 18 months | 65–75% | 48–56 lb | 68–79 lb | 88–102 lb |
The first month is the fastest — you are on a liquid and puréed diet and typically lose 10–15% of your excess weight. The pace slows month by month as your body approaches its new set point. For a patient with about 75 lb of excess weight:
| Period | Average loss per month | Cumulative %EWL |
|---|---|---|
| Month 1 | 8–11 lb | 10–15% |
| Months 2–3 | 5–8 lb | 25–35% |
| Months 4–6 | 5–6 lb | 45–55% |
| Months 7–12 | 2–3 lb | 60–70% |
| Months 13–18 | ≈1 lb | 65–75% |
It depends on your excess weight. At 60–70% EWL in the first year:
Patients with a BMI above 50 lose more pounds but often a slightly smaller percentage, which is why the surgeon may recommend SADI-S or a duodenal switch instead. Results depend on adherence to the diet, protein intake, activity and follow-up.
| Procedure | %EWL at 12 months | %EWL at 18 months | Compared with the sleeve |
|---|---|---|---|
| Gastric sleeve | 60–70% | 65–75% | — |
| Gastric bypass (RYGB) | 65–75% | 70–80% | ≈ +5%; better for reflux and diabetes |
| Mini gastric bypass | 70–85% | 75–85% | +10–15%; single anastomosis |
| SADI-S | 75–85% | 80–90% | +15%; often for BMI 50+ or as a second step |
| SASI bypass (transit bipartition) | 75–85% | 78–88% | +15%; strong metabolic results |
| Gastric band (Lap-Band®) | 40–50% | 42–52% | −20%; higher revision rate |
Starting BMI (higher BMI = more pounds, slightly lower %EWL) · Age and metabolism · Type 2 diabetes and medications · Protein and hydration (60–80 g of protein a day protects muscle and keeps loss on track) · Activity (walking from day 1, strength training from month 2) · Follow-up with your surgeon and nutritionist at 1, 3, 6 and 12 months. Patients who keep all follow-ups lose on average 10–15% more of their excess weight than those who don’t.
About 10–15% of your excess weight in the first month, 25–35% by month three and 45–55% by month six. For 75 lb of excess weight that is roughly 8–11 lb in the first month and 5–8 lb per month during months two and three.
The "three-week stall" is normal: your body replaces glycogen and water after the initial drop. A second plateau around month three is also common. Keep protein high, stay hydrated, avoid grazing, and the loss resumes within one to three weeks.
No. It is the range most patients achieve when they follow the program. Some lose more, some less. Very high starting BMI, uncontrolled diabetes, certain medications and skipping follow-ups reduce results.
On average about 5% more excess weight (65–75% vs 60–70% at one year), and the bypass controls reflux and diabetes better. The sleeve is simpler and carries fewer nutritional risks. Compare both in the calculator above.
Generally a BMI of 35+ with obesity-related conditions, or 40+ without them; many centers also treat BMI 30–35 with type 2 diabetes. Take our free 2-minute medical questionnaire and Dr. López will review your case.
Most patients keep 55–65% of their excess weight off at five years. Regain is usually gradual and tied to habits; when it is significant, a conversion to bypass or SADI-S is an option — see the revision options in the calculator.
Ranges in this tool are estimates based on the literature above and ALO Bariatrics’ clinical experience. Individual results vary. This calculator is educational and is not a medical diagnosis or a guarantee of results.
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