Gastric Sleeve Weight Loss Calculator

Percent excess weight loss (%EWL) compares the weight you have lost with the weight you had to lose to reach a BMI of 25. The formula is: %EWL = (starting weight − current weight) ÷ (starting weight − ideal weight at BMI 25) × 100. This %EWL calculator uses that same clinical formula, so it doubles as an excess weight loss calculator you can reuse at every follow-up visit to compare gastric sleeve before and after weight.

Published studies report a typical range of about 50–60% excess weight loss at 12–24 months after sleeve gastrectomy, with wide individual variation. This gastric sleeve weight loss calculator shows that typical range as a p25–p75 band — not a promise. Your surgical team can tell you what target is realistic for your starting BMI and health.

A commonly quoted gastric sleeve weight loss timeline: rapid loss in the first 3 months (often around 30% EWL), about 45–50% EWL by 6 months, then a slower phase toward roughly 57–60% EWL at 12 months, with a plateau around 12–18 months. Our gastric sleeve weight loss chart draws this as a smooth typical curve with a p25–p75 band, because real gastric sleeve weight loss month by month varies widely.

In bariatric literature, reaching 50% or more excess weight loss at 12–24 months is often described as a successful result. EWL after bariatric surgery above 75% sits well above the typical range. If your %EWL is below 25% at 12 months, published guidance suggests discussing it with your surgical team.

Bariatric studies conventionally define excess weight against the upper limit of a normal BMI (25). It is a statistical convention, not a personal prescription — this ideal body weight BMI 25 calculator approach keeps your %EWL comparable with published results.

Most cohorts show the steepest loss in months 0–6 and a gastric sleeve weight loss plateau between 12 and 18 months. A gastric sleeve weight loss stall in the first months can be normal; persistent stalls are worth raising with your clinic.

Yes. Enter your starting weight and height without a current weight to see a pure projection: expected weight loss after sleeve gastrectomy at 6, 12, 18 and 24 months, plus BMI milestones. It answers 'how much weight can you lose with gastric sleeve' only as a typical range, never as a personal promise.

Clinics often report 1–2 kg (2–4 lb) per week in the first 6–8 weeks for many patients — that is the steep part of the curve, before the rate slows. This tool models gastric sleeve weight loss per week only implicitly: its monthly curve starts at month 0, so very-early weekly swings are smoothed out.

Yes — this gastric sleeve weight loss calculator kg/lb toggle converts everything for you. Enter height in cm or ft/in and weight in kg or lb; projections are computed in metric and converted back for display.

The tool estimates when the typical median trajectory crosses BMI 30 and BMI 25 — two common gastric sleeve weight loss milestones. 'Not in typical range' means the median published trajectory does not reach that BMI within 24 months; it is not a verdict on you.

This tool models weight loss after gastric sleeve surgery only, using post-surgical %EWL trajectories. For diet-and-exercise planning, use our BMI weight loss planner or TDEE calculator instead — different physiology, different math.

No. This is an educational projection — not medical advice. Weight loss after surgery varies; follow your surgical team's plan. If anything here conflicts with your clinic's guidance, your clinic wins.