Results update live as you type after first calculation.
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Enter your height and sex, then tap Calculate Ideal Weight to see results across five clinical formulas.
Ideal Body Weight — Devine Formula (Most Used)
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lbs
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Healthy BMI Range
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lbs (BMI 18.5–24.9)
Formula Average
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across 5 formulas
Frame-Adjusted IBW
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medium frame
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Your Weight vs Ideal
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All 5 Formulas Compared
Formula
Year
Ideal Weight
vs Devine
Formula Comparison Chart
Visual comparison of all five IBW formulas and the WHO healthy BMI range for your height.
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Adjusted Body Weight (AdjBW)
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Your current weight exceeds your IBW by more than 30%. AdjBW is shown for clinical reference only. Consult a healthcare professional for personalised guidance.
The concept of an ideal body weight (IBW) has been studied for over 60 years. Originally developed to help clinicians calculate drug doses, IBW formulas are now widely used as reference targets for weight management and health screening. Our ideal body weight calculator aggregates five of the most respected clinical formulas — Devine, Robinson, Miller, Hamwi, and Peterson — and presents results side by side with the WHO's healthy body weight index range. Understanding the differences between these methods helps you set realistic, evidence-based weight goals.
The Five IBW Formulas
All five formulas follow the same structure: a base weight for a person 5 feet tall, plus a fixed increment per inch above 5 feet. They differ in base values and increments determined by separate research teams across different decades.
Devine (1974) — Most Widely Used
Men: IBW = 50.0 kg + 2.3 kg × (inches − 60) Women: IBW = 45.5 kg + 2.3 kg × (inches − 60)
Foundation of pharmacy dosing worldwide.
Robinson (1983)
Men: IBW = 52.0 kg + 1.9 kg × (inches − 60) Women: IBW = 49.0 kg + 1.7 kg × (inches − 60)
Miller (1983)
Men: IBW = 56.2 kg + 1.41 kg × (inches − 60) Women: IBW = 53.1 kg + 1.36 kg × (inches − 60)
Hamwi (1964)
Men: IBW = 48.0 kg + 2.7 kg × (inches − 60) Women: IBW = 45.5 kg + 2.2 kg × (inches − 60)
Works for any height without the 5-foot floor limitation.
What Is the Healthy Body Weight Index?
The healthy body weight index is the weight range that corresponds to a BMI of 18.5–24.9 kg/m² for your specific height — the WHO definition of normal weight in adults. Unlike single-number IBW formulas, it gives you a range, which reflects the biological reality that a range of weights is associated with good health outcomes.
Our optimal weight calculator shows this range alongside the five IBW formulas so you can see where they converge — the overlap zone is generally the most defensible weight target.
Adjusted Body Weight
Adjusted Body Weight (AdjBW) is used clinically when a patient's actual weight exceeds IBW by more than 30%. It is important because some medications distribute partially into excess adipose tissue and cannot be dosed on IBW alone.
AdjBW Formula
AdjBW = IBW + 0.4 × (Actual Weight − IBW)
The 0.4 factor accounts for partial drug distribution into excess adipose tissue.
Body Frame Size & IBW
Body frame size affects ideal weight by ±10%. Measure your wrist circumference — men under 6.5" = small frame, 6.5–7.5" = medium, over 7.5" = large. Women under 6" = small, 6–6.5" = medium, over 6.5" = large. Our optimal weight calculator applies this adjustment automatically based on the frame you select.
Key Factors That Affect Ideal Body Weight
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Sex
Women have a lower IBW than men at the same height due to naturally lower bone density and muscle mass. All five formulas use different base values for males and females.
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Height
IBW formulas add a fixed weight increment per inch of height. The Peterson formula addresses non-linear scaling better than older formulas.
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Frame Size
Large-framed individuals naturally weigh more due to denser, heavier bones. The typical adjustment is ±10% of IBW.
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Muscle Mass
IBW formulas don't account for body composition. A highly muscular athlete may exceed their formula-based IBW while carrying very little body fat.
Limitations of IBW Formulas
- No body composition data: Formulas use only height and sex — no distinction between fat and muscle mass.
- Height floor at 5 feet: Devine, Robinson, Miller, and Hamwi produce unreliable results below 5 feet. Use Peterson for shorter individuals.
- Adults only: All five formulas are validated for adults 18+. Children use growth chart percentiles.
- Ignores fat distribution: Waist circumference is a stronger predictor of metabolic risk than total weight.
- Ethnic variability: Formulas calibrated on Western populations may not generalise globally.
Use IBW as a general orientation point — not a rigid target. The most meaningful health indicators are energy, strength, blood markers, and sustained lifestyle habits.
How to Use Your Ideal Body Weight Result
- Compare all formulas, not just one. If four out of five cluster around 160–168 lbs, that cluster is your realistic target zone.
- Cross-check with the healthy body weight index. If your IBW falls inside the BMI 18.5–24.9 range, the formula is consistent with population-level health data.
- Calculate your calorie target next. Use our Calorie Intake Calculator to find how many calories you need to move toward your target weight.
- Check your current BMI. Our BMI Calculator tells you where you currently stand in the WHO classification system.
- Factor in frame size. Use the wrist measurement guide in the sidebar to adjust your result by ±10%.
- Set incremental targets. Focus on 5–10% body weight milestones — each brings measurable health benefits.
Frequently Asked Questions
What is the ideal body weight for my height?
IBW depends on your height and sex. Using the Devine formula: a 5'10" man has an IBW of ~166 lbs (75 kg); a 5'6" woman has an IBW of ~130 lbs (59 kg). Different formulas produce slightly different values — our ideal body weight calculator shows all five side by side. Always treat results as a reference range, not a precise target.
How is this optimal weight calculator different from a BMI calculator?
A BMI calculator tells you where you currently are. An optimal weight calculator tells you where your target is — the weight associated with good health for your height and sex. Use both together for a complete picture.
What is the healthy body weight index?
The healthy body weight index is the weight range corresponding to a BMI of 18.5–24.9 kg/m² for your height — the WHO definition of normal weight. It is calculated as: min = 18.5 × height²(m²); max = 24.9 × height²(m²). Our calculator displays this range in both the results panel and the comparison chart.
Which ideal body weight formula should I use?
Devine is the most widely cited in clinical and pharmacy literature. Peterson (2016) is the most modern and handles all heights without the 5-foot floor limitation. For practical purposes, look at where the five formulas converge — that cluster is your most defensible ideal weight range.
What is Adjusted Body Weight and when is it used?
AdjBW is used by pharmacists and clinicians when actual weight exceeds IBW by more than 30%. Formula: AdjBW = IBW + 0.4 × (Actual − IBW). It is a pharmacological dosing tool, not a weight-loss target. Our calculator displays it automatically when applicable.
Medical Disclaimer: The ideal body weight, optimal weight, and adjusted body weight values generated by this calculator are estimates based on published clinical formulas and are provided for educational purposes only. They are not a substitute for professional medical advice. Always consult a qualified healthcare professional before making changes to your diet, exercise, or health management plan.
