How the estimate works

Excess weight is your current weight minus the weight that gives a BMI of 25. The calculator applies the typical percentage of excess weight lost (%EWL) reported in clinical studies for each procedure. For example, a gastric sleeve typically removes about 60–70% of excess weight within 12–18 months, a gastric bypass about 70–75%, a duodenal switch about 80% and a gastric band about 40–50%. Results are slightly lower over age 60. Your real results depend on your health, diet and activity.