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Calculate your ideal body weight using multiple scientific formulas including Robinson, Miller, Devine, and Hamwi.
Expert reviewer: CalculatorApp.me Health Editorial Team
Results will appear here after calculation
Reviewed by CalculatorApp.me Health Editorial Team · Updated March 2026 · 10 min read
4
Scientific Formulas
±10%
Frame Adjustment
60+
Years of Research
12
FAQ Answers
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Ideal body weight (IBW) is a clinically-derived target weight based on height and biological sex. Originally developed to standardize medication dosing, IBW is now a core metric in preventive care, sports nutrition, and rehabilitation planning.
Unlike BMI, which is a ratio, IBW gives you an absolute weight range in kg or lbs — making goal-setting concrete and measurable. Per the WHO, 1.9 billion adults are overweight while 462 million are underweight — IBW supports both contexts.
🔗 Related tools on this site
5 Evidence-Based Facts
♂ Men: 50 + 2.3 × (inches − 60)
♀ Women: 45.5 + 2.3 × (inches − 60)
Original drug-dosing formula. Most cited in pharmacokinetics literature.
♂ Men: 52 + 1.9 × (inches − 60)
♀ Women: 49 + 1.7 × (inches − 60)
Broader population sample. Preferred in wellness and fitness contexts.
♂ Men: 56.2 + 1.41 × (inches − 60)
♀ Women: 53.1 + 1.36 × (inches − 60)
Most generous values. Best for taller individuals and large frames.
♂ Men: 48 + 2.7 × (inches − 60)
♀ Women: 45.5 + 2.2 × (inches − 60)
First bedside clinical formula. Foundational for dietetics education.
Clinical Disclaimer: These formulas do not account for muscle mass, bone density, ethnicity, or body fat distribution. Athletes routinely exceed IBW while being metabolically healthy. Pregnant women, under-18s, and those with chronic conditions should consult a licensed healthcare provider before setting any weight targets.
Ideal weight science spans 160 years — from actuarial insurance tables to ICU ventilator protocols. Understanding its history helps you interpret your results with the right clinical context.
Metropolitan Life Insurance published the first height-weight tables correlating body weight with longevity. Limited to White, middle-class American men, but established the height-based weight norm paradigm still used today.
Dr. G. J. Hamwi created the first practical bedside formula for dietitians: 106 lbs for men or 100 lbs for women at 5 ft, adding 6 or 5 lbs per additional inch. Easy to calculate mentally during ward rounds without a calculator.
Dr. B. J. Devine solved the drug-overdose problem for obese patients by publishing an IBW formula specifically for calculating medication doses with narrow therapeutic windows (aminoglycosides, vancomycin, anesthesia agents).
Two independent research groups refined IBW coefficients for broader populations. Robinson is preferred for lifestyle use; Miller is most generous and suits taller individuals.
The National Institutes of Health published BMI-based classification guidelines, creating a parallel system to IBW. Both tools are now used together in clinical settings.
The landmark ARDSNet study proved that IBW-based mechanical ventilator tidal volume settings reduced ICU mortality by 22%. Published in the New England Journal of Medicine.
Modern tools combine IBW with body composition, waist metrics, and cardiometabolic markers. Multi-formula comparison — like this calculator — is now the evidence-based standard.
Example A
Male · 5 ft 10 in · Medium Frame
| Formula | kg | lbs |
|---|---|---|
| Devine | 73.0 kg | 160.9 lbs |
| Robinson | 71.0 kg | 156.5 lbs |
| Miller | 70.3 kg | 155.0 lbs |
| Hamwi | 75.0 kg | 165.3 lbs |
Avg: 72.3 kg
70.3 – 75.0 kg
Example B
Female · 5 ft 4 in · Small Frame (−10%)
| Formula | kg | lbs |
|---|---|---|
| Devine | 54.7 kg | 120.6 lbs |
| Robinson | 55.8 kg | 123.0 lbs |
| Miller | 58.5 kg | 129.0 lbs |
| Hamwi | 54.3 kg | 119.7 lbs |
Avg: ~50.2 kg
Adjusted for small frame
Example C
Female · 5 ft 8 in · Large Frame (+10%)
| Formula | kg | lbs |
|---|---|---|
| Devine | 63.9 kg | 140.9 lbs |
| Robinson | 62.6 kg | 137.9 lbs |
| Miller | 64.0 kg | 141.1 lbs |
| Hamwi | 63.1 kg | 139.1 lbs |
Avg: ~69.7 kg
Adjusted for large frame
Each metric measures something different. Use them as a layered system — not as competing alternatives — for the most accurate health picture. Compare with our BMI Calculator and Body Fat Calculator.
| Metric | Measures | Best For | Key Limitation |
|---|---|---|---|
| ⚖️ IBW | Estimated target weight (kg/lbs) from height + sex | Goal setting, drug dosing, clinical planning | No body composition; height-only input |
| 📊 BMI | Weight ÷ Height² ratio (kg/m²) | Population screening, quick risk triage | Misclassifies athletes; no fat distribution info |
| 💪 Body Fat % | Percentage of mass that is fat tissue | Composition analysis, athletic performance | Requires DEXA/BIA device for accuracy |
| 📏 Waist Circumference | Abdominal girth (proxy for visceral fat) | CV & metabolic risk (WHO: >88 cm women, >102 cm men) | Single dimension; not full composition picture |
Drugs with narrow therapeutic windows (gentamicin, vancomycin, chemotherapy, anesthesia) are dosed on IBW to prevent toxicity in obese patients. This remains the most clinically validated use of the Devine formula.
Critical care teams use IBW to calculate calorie and protein targets for enteral/parenteral nutrition. Using actual weight in obese patients overestimates energy needs, worsening hyperglycemia and infection risk.
Ventilator tidal volumes are set by PBW (= IBW). The ARDSNet trial (NEJM 2000) proved 6 mL/kg IBW-based settings reduced ICU mortality by 22% vs. actual-weight-based settings. NEJM ARDSNet Trial ↗
Surgical eligibility typically requires 100+ lbs over IBW or BMI ≥ 40. Post-op progress is tracked as "excess weight loss %" relative to IBW — a standard outcome metric in bariatric research.
Registered Dietitians set calorie and macro targets based on IBW rather than actual weight to create sustainable plans. The Harris-Benedict and Mifflin-St Jeor equations are often run using IBW in overweight patients. See our BMR Calculator →
Coaches use IBW to set realistic category targets for weight-class sports and discuss body composition goals. Endurance athletes often target below-IBW weights to optimize power-to-weight ratio under sports medicine supervision.
IBW formulas are most accurate. Lean mass is at peak; standard ranges align well with health outcomes.
Sarcopenia begins (3–5% muscle/decade). May be "in IBW range" but have high body fat. Add waist measurement.
The "obesity paradox" (Flegal et al., JAMA 2013) suggests slightly higher weight may be protective. Prioritize lean mass over strict IBW adherence.
♂ Men
♀ Women
Pai & Paloucek (2000)
Annals of Pharmacotherapy
Traced the origins of all four IBW equations; recommended reporting multiple formula variants to avoid clinical bias.
ARDSNet Trial (2000)
New England Journal of Medicine
IBW-based ventilator volumes (6 mL/kg) cut ICU mortality by 22% vs. actual-weight volumes. Landmark critical care evidence.
NDPP — Knowler et al. (2002)
New England Journal of Medicine
5–7% weight loss reduced incidence of Type 2 diabetes by 58%, validating IBW-range lifestyle goals.
Flegal et al. (2013)
JAMA
Meta-analysis of 2.88 million adults: slight overweight (BMI 25–30) associated with lower all-cause mortality over 65 — the obesity paradox.
Kyle UG et al. (2003)
Clinical Nutrition
BIA study: IBW formulas underestimate lean mass in taller individuals, reinforcing the need for frame-size adjustments.
WHO Waist Report (2011)
WHO Press
Established global waist-circumference risk thresholds (>88 cm women, >102 cm men) as complement to IBW assessment.
Myth
Everyone at the same height should weigh exactly the same.
Fact
IBW formulas provide a range, not a single target. Frame size, bone density, muscle mass, and health status all legitimately shift what is appropriate. Even the four standard formulas disagree by up to 5 kg for the same person.
Myth
If I am over my IBW, I am unhealthy.
Fact
Athletes with high muscle mass routinely exceed IBW while having excellent cardiometabolic markers. IBW is a planning guide, not a clinical diagnosis. Health involves blood markers, fitness, and body composition — not just the scale.
Myth
IBW formulas are outdated and no longer clinically used.
Fact
IBW-based dosing remains the standard in pharmacokinetics, ICU ventilation, and critical care nutrition. The ARDSNet ventilator trial saved thousands of lives using IBW. Medical schools still teach these formulas worldwide.
Myth
Reaching IBW as quickly as possible is the best strategy.
Fact
Rapid weight loss (>1 kg/week sustained) causes lean mass loss, hormonal disruption, nutrient deficiencies, and metabolic rate suppression. Gradual change consistently outperforms fast approaches for long-term maintenance.
Myth
IBW and BMI measure the same thing.
Fact
IBW is an absolute weight in kg or lbs. BMI is a dimensionless ratio (kg/m²). They correlate but serve different purposes. A very tall person can exceed IBW with a normal BMI; a short person can be at IBW with a slightly elevated BMI.
This page is reviewed periodically by our Clinical Advisory Board. All content is for educational use only and does not constitute medical advice. For personalized guidance consult a qualified healthcare professional.
Use these together with Ideal Weight for a complete health picture.
Body mass index — population risk screening
Calculate →Estimate body fat percentage by measurement
Calculate →Daily calorie needs at rest and with activity
Calculate →Daily calorie target for sustainable weight loss
Calculate →Estimate body fat percentage from body measurements
Calculate →Basal metabolic rate and daily calorie needs
Calculate →BMI, body fat, calorie needs, heart rate zones, macros & more — all free, no sign-up required.
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