The honest answer in seconds, using the four physician-recognized formulas and the healthy BMI range. Then see exactly when you'll get there on tirzepatide or semaglutide.
Each formula uses a slightly different baseline and per-inch increment. Clinicians cite Devine most often; the others are useful for cross-check.
Your lean body mass is the muscle, bone, organs, and water weight you want to preserve. Your ideal weight is whatever weight puts you at your target leanness while keeping that LBM intact.
156 ÷ (1 − 0.12) = 177 lbs. This is the weight that lets you keep every pound of muscle while reaching your target leanness.The four physician-recognized ideal-weight formulas, Devine, Robinson, Miller, and Hamwi, return values within ~5% of each other for most adults. They're calibrated to average-population body composition, so muscular individuals should switch to Lean Body Mass ÷ (1 − target body fat %) instead. For example, a 200-lb man at 22% body fat targeting 12% body fat: 156 ÷ 0.88 = ~177 lb ideal weight.
Source: Devine BJ. Drug Intell Clin Pharm 1974 · Pai MP, Paloucek FP"Ideal body weight" is a clinical concept. The four formulas this calculator uses were each developed by physicians or pharmacologists to give a single number that drugs could be dosed against, long before BMI charts were standard. Each formula uses a baseline weight at 5 feet plus a per-inch increment. The differences in their coefficients reflect different population samples and slightly different definitions of what "ideal" meant in their era.
Originally developed by B.J. Devine for calculating gentamicin doses. Despite never being formally validated in a peer-reviewed paper, this is the most widely-cited ideal weight formula in modern clinical use, present in pharmacy software, ICU drug dosing protocols, and medical education.
Published by J.D. Robinson in American Journal of Hospital Pharmacy. Slightly higher baseline than Devine, lower per-inch slope. Generally produces results within 5% of Devine for average heights.
Published the same year as Robinson by D.R. Miller. Highest baseline of the four, but the lowest per-inch slope, so it under-weighs taller individuals relative to the others.
The oldest of the four, originally developed by G.J. Hamwi for dietary planning in diabetic patients. Has the steepest per-inch slope, produces the highest values for taller individuals.
Why we show all four. Each formula has an inherent bias, none are perfect. Physicians cross-check them and average them in practice. Showing the spread tells you the honest answer is a range, not a single point.
BMI of 18.5-24.9 is the WHO-defined "healthy weight" range. We multiply it by your height squared to get a weight range you can sit comfortably within. This range is wider than any single ideal-weight formula and reflects the reality that healthy weight isn't a single number, it's a band.
Strength athletes, bodybuilders, and trained individuals routinely have 15-30 lbs more lean tissue than the population average for their height. The four classical formulas, and BMI itself, were calibrated to average body composition, so they systematically under-shoot ideal weight for muscular populations. The fix is simple math: hold lean body mass constant, pick a target body fat percentage, and solve for the corresponding total weight.
The formula: Ideal weight = Lean body mass ÷ (1 − target body fat %). A 200 lb male at 22% body fat has 156 lbs of LBM. To reach 12% body fat, his ideal weight is 156 ÷ 0.88 = 177 lbs, about 10 lbs higher than what Devine would predict for the same height. That extra 10 lbs is the muscle the standard formulas don't see.
This is also the right framing for anyone using a GLP-1 medication: the goal isn't to lose weight, it's to lose fat while keeping muscle. Pairing your medication with adequate protein intake (1g per pound of LBM) and resistance training 3-4×/week is what makes the LBM-based ideal achievable rather than aspirational. Standard ideal-weight formulas treat all weight as equivalent; the LBM approach respects the muscle you've earned.
The honest answer: average them. Each formula has a known bias, and taking the average across all four, plus the healthy BMI range as a sanity check, gives you a more reliable target than any single formula. If you must pick one, Devine is the most clinically cited.
Different sites use different formulas. Some use only Devine. Some use BMI 22 as a target. Some use the J.D. Robinson formula. We show all four major formulas plus the BMI range so you can see the spread instead of being given one cherry-picked number.
Toggle Athletic / muscular mode at the top of the calculator. It uses your lean body mass (LBM) and target body fat percentage to compute a healthy weight that preserves muscle. The math: ideal weight = LBM ÷ (1 − target body fat %). A 200-lb male at 22% body fat has ~156 lbs of LBM. To reach 12% body fat (athletic), his ideal weight is 156 ÷ 0.88 = 177 lbs, much higher than what the standard formulas would say. If you don't know your body fat %, use the Body Fat Calculator first.
Standard mode uses the four physician formulas (Devine, Robinson, Miller, Hamwi) plus the healthy BMI range. These were calibrated to average-population body composition and are accurate for most untrained individuals. Athletic mode uses your actual lean body mass and a target body fat percentage. It's the right approach for trained athletes, lifters, and anyone whose muscle mass is meaningfully above population average, because the standard formulas systematically under-estimate ideal weight for muscular people.
For men: 10-14% is athletic and visibly lean (visible abs); 15-17% is fit; 18%+ is healthy lean. Below 8% is stage / competition territory and not sustainable year-round. For women: 16-20% is athletic; 21-24% is fit; 25-28% is healthy lean. Below 15% women may experience hormonal disruptions; below 12% is competition territory. Most healthy adults thrive at the "fit" or "healthy lean" tier, going lower is a stylistic choice, not a health requirement.
Aim for the average as a long-term anchor. Hitting the lowest end of the range is rarely necessary and often harder to maintain. The healthy-BMI range exists precisely because health outcomes are similar across the band, being at the high end of healthy is just as cardiovascularly protective as the low end for most people.
SURMOUNT-1 trial data on tirzepatide showed an average 20.9% body weight reduction at 72 weeks. STEP-1 on semaglutide showed 14.9% at 68 weeks. For most users, that's enough to close the gap to ideal weight. Use our Goal Weight Date Calculator to see the projected timeline.
Yes, each formula has a separate equation for women, with a lower baseline (because women on average have less lean mass than men of the same height). Hamwi tends to over-weigh women relative to the others; Devine and Robinson are usually closer to the middle.
No, and this matters. "Ideal weight" is a clinical reference. "Goal weight" is what you decide based on your goals, body composition, and health context. Most people set a goal weight slightly above clinical ideal weight (e.g., upper end of healthy BMI) because it's easier to maintain and often better for athletic performance.
Ideal weight is the anchor. These tools fill in the rest, body composition, calorie targets, hormones, and the timeline to get there.
Hand-picked guides on closing the gap to ideal weight, and what to do once you're there.
In the SURMOUNT-1 trial, FDA-approved branded tirzepatide produced an avg 20.9% body-weight reduction at 72 weeks. Compounded preparations are not FDA-approved. If your ideal-weight gap is 20+ lbs, a physician-supervised GLP-1 protocol can help close it while supporting lean-mass preservation when paired with adequate protein and training.
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How this tool calculates
Ideal body weight is estimated using three validated clinical formulas (Devine, Robinson, and Miller), with results averaged for a more robust estimate. These formulas were originally developed for drug dosing calculations and remain the clinical standard.
Peer-reviewed sources
Important. This tool is provided for educational purposes only and does not constitute medical advice, diagnosis, or treatment. The tool does not prescribe medication, recommend specific dosing, or substitute for clinical evaluation. Compounded medications referenced anywhere on this site are not FDA-approved; the FDA does not verify the safety, effectiveness, or quality of compounded drugs. Treatment decisions are made only by a licensed U.S. physician after individual patient evaluation.