Gastric Sleeve Weight Loss
Calculate expected weight loss after gastric sleeve bariatric surgery from your height, weight, and surgery type. View BMI, ideal weight, and projected weight.
About This Calculator
The Gastric Sleeve Weight Loss Calculator helps you estimate your post-operative weight loss after bariatric surgery. Enter your height, current weight, and select your surgery type to see your BMI, ideal weight, excess weight, and a personalized weight loss projection at 3, 6, and 12 months. This tool is designed for anyone considering gastric sleeve surgery or other bariatric procedures who wants to understand their potential weight loss outcomes.
The calculator uses the standard bariatric formula: your ideal weight is calculated at a BMI of 24.9 (the upper end of the healthy range), and excess weight is your current weight minus your ideal weight. Each surgery type has a different expected excess weight loss percentage — gastric sleeve leads at 70%, followed by gastric bypass and duodenal switch at 65%, Lap-Band at 40%, and gastric balloon and AspireAssist at 30%. The timeline assumes 40% of total loss is achieved by 3 months, 70% by 6 months, and 100% by 12 months.
For more detailed information, consult your bariatric surgeon or visit resources like the American Society for Metabolic and Bariatric Surgery (ASMBS). This calculator provides estimates only and should not replace professional medical advice.
Frequently Asked Questions
How is weight loss after gastric sleeve calculated?
The calculator finds your ideal weight at BMI 24.9, then subtracts it from your current weight to get excess weight. For gastric sleeve surgery, you can expect to lose approximately 70% of your excess weight within the first 12 months. The projection assumes 40% of total loss by 3 months and 70% by 6 months.
Do I qualify for gastric sleeve surgery?
You typically need a BMI above 40 to qualify, or above 35 with an obesity-related condition such as type 2 diabetes, high blood pressure, sleep apnea, high cholesterol, or joint issues. You must also be healthy enough for general anesthesia and psychologically ready for lifestyle changes after surgery.
How much weight can you lose with a gastric sleeve?
Gastric sleeve surgery allows patients to lose approximately 70% of their excess body weight within 12 months. This is better than Lap-Band (40%), Gastric Balloon (30%), and AspireAssist (30%), and comparable to Gastric Bypass (65%) and Duodenal Switch (65%).
What is the average monthly weight loss after gastric sleeve?
Weight loss is fastest in the first 3 months (about 40% of total expected loss), continues steadily through months 3-6 (reaching 70% of total loss), and slows down between months 6-12 (reaching 100% of total expected loss). Individual results vary based on diet, exercise, and adherence to lifestyle changes.
Is gastric sleeve or gastric bypass better for weight loss?
Gastric sleeve typically results in about 70% excess weight loss, while gastric bypass achieves about 65%. Gastric sleeve is more popular because it is simpler and has fewer long-term nutritional complications. However, gastric bypass may be better for patients with severe GERD or type 2 diabetes. A consultation with a bariatric surgeon is essential.
Can you regain weight after gastric sleeve surgery?
Yes, weight regain is possible if dietary and exercise habits are not maintained. Long-term success requires adherence to a balanced diet, regular physical activity, and follow-up appointments with your healthcare team. The procedure is a tool — lifestyle changes are essential for maintaining results.