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Turn your pounds lost into percent of body weight — the number that actually matters clinically — and see exactly where it lands on the scale doctors and drug trials use. Then compare yourself, fairly, to Wegovy and Zepbound.
Enter your starting and current weight to see the number that actually matters clinically: percent of total body weight lost — the same yardstick every GLP-1 trial and FDA approval uses. Everything runs on your device.
This is the threshold the FDA uses to approve weight-loss drugs, and where blood sugar, blood pressure, and triglycerides start to measurably improve. It counts, even if it feels modest.
You are 2 lb from crossing the 10% mark.
Trial figures are on-treatment averages at the studied dose. A third of people lose more, a third less — being below the average is common and not a failure.
Weight-loss percentage is the share of your body weight you have lost: (starting weight − current weight) ÷ starting weight × 100. Worked example: going from 240 to 218 lb is 22 lb, and 22 ÷ 240 × 100 = 9.2%. It is the single most useful number to track because it is comparable — 30 lb lost is a very different achievement at 180 lb than at 340 lb, but as a percentage the comparison is fair. That is exactly why every clinical trial, treatment guideline, and drug label reports results as percent of total body weight(%TBWL), not pounds: 5% is the FDA’s approval bar for a weight-loss drug, 10% is where cardiometabolic benefits widen, ~15% was the Wegovy trial average (STEP 1), and ~21% was Zepbound’s top dose in SURMOUNT-1. The calculator above places your number on that same ladder.
Your percentage matters because medicine has attached specific health meaning to specific levels of loss:
| Loss | Why it matters |
|---|---|
| 5% | The FDA’s minimum bar to approve a weight-loss drug. Blood sugar, blood pressure, and triglycerides start to measurably improve. |
| 10% | Broader payoff: improvements in obstructive sleep apnea and fatty-liver disease, plus durable blood-pressure and cholesterol gains. |
| 15% | The average total loss in STEP 1 (Wegovy). A large reduction in the risk of progressing to type 2 diabetes. |
| 20%+ | The average on the top dose of Zepbound in SURMOUNT-1 — a range that, before GLP-1s, usually meant bariatric surgery. |
The most useful thing this number does is separate health progress from goal-weight progress. You can be discouraged that you are “only” down 6% and not realize you have already crossed the threshold where your blood pressure and A1c are improving. The health wins arrive early — often by 5–10% — long before the goal-weight figure you have in mind.
If you are on or considering a GLP-1, the honest comparison is against the trial averages, shown as a range. Wegovy (semaglutide) averaged about 15% in STEP 1; Zepbound (tirzepatide) about 21% on its top dose in SURMOUNT-1. But a third of people lose more and a third less, so landing below the average is ordinary. For the week-by-week forecast on your own weight, use the GLP-1 weight-loss projector; to see how the two drugs stack up, read Wegovy vs Zepbound. Stalled before your goal? The plateau diagnostic walks through the usual causes.