Gastric Sleeve Weight Loss Calculator

Your BMI helps identify your current health range (normal, overweight, or obese) and serves as a baseline to track improvement after bariatric surgery.

2. Ideal Weight Using the Devine Formula

Once BMI is established, the calculator estimates your ideal weight — the healthy target based on your height:

• For Men: 50 + 2.3 × (height in inches − 60)

• For Women: 45.5 + 2.3 × (height in inches − 60)

This formula is widely used in clinical settings.
Your excess weight = Current Weight − Ideal Weight.

3. Expected Weight Loss (EWL%) by Procedure Type

The tool then estimates your expected % of excess weight loss (%EWL) — a standard measure in bariatric surgery outcomes.

Example:

If you weigh 120 kg, your ideal weight is 70 kg. Your excess weight is 50 kg.
At 70% EWL, your expected loss = 35 kg, reaching 85 kg in 12–18 months.

Bariatric Weight Loss Calculator by Month

The bariatric weight loss calculator by month allows patients to estimate progress over time — ideal for those who want motivation during recovery.
Typically, sleeve patients experience a rapid loss in the first 6 months, then a slower but steady reduction.

This data is based on outcomes published by ASMBS and JAMA Surgery.

What Affects Your Gastric Sleeve Weight Loss Results?

While the calculator provides realistic predictions, actual results depend on your lifestyle and physiology.
Here are the most important factors influencing success after bariatric surgery:

• Initial BMI: Higher BMI patients tend to lose more total weight but smaller %EWL.

• Age: Younger patients often see faster results.

• Gender: Men may lose slightly faster initially due to higher lean mass.

• Post-op diet: Following the surgeon’s nutrition plan is essential.

• Physical activity: Moderate exercise accelerates fat loss and preserves muscle.

• Metabolism & hormones: These influence weight loss speed.

• Follow-up care: Regular visits and labs help ensure long-term success.

Why This Calculator Is Clinically Reliable

Our bariatric surgery expected weight loss calculator uses published datasets from:

• American Society for Metabolic and Bariatric Surgery (ASMBS)

• MBSAQIP (Metabolic & Bariatric Surgery Accreditation and Quality Improvement Program)

• PubMed-indexed clinical trials (2018–2024)

• JAMA Surgery reports on long-term outcomes

It’s designed to be educational and medically referenced, not promotional.
Unlike generic online tools, this one aligns with doctor-reviewed methodology, EWL standards, and ADA-compliant UI.

Gastric Sleeve vs. Other Bariatric Procedures

Your choice of surgery impacts your expected results. The calculator adjusts accordingly, making it useful for pre-op and post-op patients alike.

Frequently Asked Questions (FAQ)

How much weight will I lose with gastric sleeve surgery?

Most patients lose 60–70% of their excess body weight within 12–18 months.
However, results depend on adherence to diet, exercise, and follow-up care.

Can I use this calculator after my surgery?

Yes. It’s ideal for tracking your bariatric surgery weight loss month by month and comparing your results to clinical averages.

Is it only for gastric sleeve patients?

No — it also works as a bariatric sleeve weight loss calculator, excess weight loss calculator, bariatric surgery, and weight loss calculator after bariatric surgery for bypass and duodenal switch patients.

How accurate is it?

The calculator uses average EWL% data from peer-reviewed studies.
Individual outcomes can vary, but they provide a dependable benchmark.

References & Clinical Sources

1. ASMBS Clinical Guidelines, 2024 Update

2. MBSAQIP Bariatric Outcomes Report

3. JAMA Surgery – Long-Term Weight Loss Trends After Sleeve Gastrectomy (2023)

4. PubMed – Gastric Bypass vs Sleeve EWL Comparison (2022)

5. Mayo Clinic – Bariatric Surgery Aftercare Recommendations

6. Cleveland Clinic – Bariatric Nutrition and Lifestyle Management