Gastric Sleeve Weight Loss Calculator

Your details

Used for the Devine ideal body weight formula, which is sex-specific.
Your weight before surgery (or your current weight if tracking progress).
kg
Your standing height without shoes.
cm
Expected weight at 18 monthsExcellent expected outcome
78.9kg

Projected weight at 18 months post-surgery (68% EWL benchmark).

BMI (before surgery)42.5kg/m²
Ideal body weight (Devine)59.6kg
Excess weight60.4kg
%EWL at 18 months1%
%TBWL at 18 months0%
BMI at 18 months28kg/m²
Weight at 3 months101.9kg
Weight at 6 months89.8kg
Weight at 12 months80.8kg
Weight at 24 months77.7kg
  • 3 months (30% EWL)
  • 6 months (50% EWL)
  • 12 months (65% EWL)
  • 18 months (68% EWL)
  • 24 months (70% EWL)

Expected loss of 68% of excess weight by 18 months

  • At the 18-month mark, gastric sleeve patients lose about 68% of their excess weight on average, putting your projected weight at 78.9 kg.
  • Your BMI is estimated to drop from 42.5 to 28.0 kg/m² - a reduction of 14.5 points.
  • Total body weight loss at 18 months is projected at 34%. Your ideal body weight (Devine formula) is 59.6 kg.
  • Individual results vary based on diet adherence, physical activity, metabolic rate, and surgical technique. These projections represent published clinical averages.

Next stepThese numbers are population-level averages. A bariatric surgeon and registered dietitian can give you a personalised estimate based on your full medical history.

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