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Enter your stats to get the exact calories to eat per day to lose weight at the pace you pick — 0.5, 1, or 1.5 lb a week. Then see the part generic calculators leave out: what a GLP‑1 like Wegovy or Zepbound adds on top, grounded in trial data.
Enter your age, height, and weight above to see your BMR, maintenance calories, and a GLP-1 weight-loss projection.
BMR uses the Mifflin-St Jeor equation. Estimates are general nutrition information, not medical or dietary advice. Inputs stay on your device — nothing is sent anywhere.
A calorie deficit means eating fewer calories than your body burns in a day. It is the one mechanism behind all fat loss — no diet, drug, or workout skips it. Your body makes up the shortfall by burning stored fat, and because roughly 3,500 calories equals a pound, a deficit of about 500 calories/day yields ~1 lb of loss per week.
To find your deficit you first need your TDEE — the calories you burn per day. We calculate it from your BMR (via the Mifflin-St Jeor equation, the dietitian standard) times an activity factor, then subtract your chosen deficit to get a daily calorie target. Prefer to start from maintenance calories? Use the TDEE calculator — same engine, framed the other way.
Knowing your number is easy; holding it is the problem. As you lose weight, hunger hormones rise and your body defends its old set-point — the biological reason most diets stall around 3–5% loss, not weak willpower. This is exactly what GLP-1 medications change: they blunt appetite so the same deficit happens with far less effort. That is why trial-average loss reaches ~15% on Wegovy (STEP 1) and ~21% on Zepbound (SURMOUNT-1), versus 3–5% for diet alone. Not sure which fits you? Take the GLP-1 quiz or compare in Wegovy vs Zepbound.