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We use 5 validated medical formulas for accuracy
⚖️ Your Ideal Weight Results
How to Calculate Ideal Body Weight
There is no single perfect formula for ideal weight — different medical and research organizations use different methods. Our calculator shows results from all 5 major validated formulas so you get a complete picture of your healthy weight range rather than a single number that may not suit your body type.
The 5 Formulas We Use:
- Devine Formula (1974) — Most widely used in clinical settings. Men: 50 + 2.3 kg per inch over 5 feet. Women: 45.5 + 2.3 kg per inch over 5 feet
- Robinson Formula (1983) — Refinement of Devine. Men: 52 + 1.9 kg per inch over 5 feet. Women: 49 + 1.7 kg per inch over 5 feet
- Miller Formula (1983) — Men: 56.2 + 1.41 kg per inch over 5 feet. Women: 53.1 + 1.36 kg per inch over 5 feet
- Hamwi Formula (1964) — Oldest formula still in use. Men: 48 + 2.7 kg per inch over 5 feet. Women: 45.5 + 2.2 kg per inch over 5 feet
- BMI Based Range — Healthy BMI of 18.5-24.9 converted to weight range for your height
Why Ideal Weight is a Range Not a Single Number
Body weight is influenced by muscle mass, bone density, body composition and frame size. Two people of the same height can have very different ideal weights depending on their build. This is why we show a range rather than one number — your ideal weight is the range within which you feel and perform your best while maintaining good health markers like blood pressure and blood sugar.
Ideal Weight Calculator — What the Formulas Mean and How to Use Them
Ideal weight formulas estimate a healthy target weight based on height and sex, providing a reference range rather than a single perfect number. Multiple formulas exist — Hamwi, Devine, Robinson and Miller — each developed for different clinical purposes and each producing slightly different results. Understanding what these numbers mean, their limitations and how they relate to broader health indicators helps you use them constructively rather than as rigid targets.
The Four Ideal Weight Formulas Compared
Each formula uses a different baseline and increment per inch of height above a reference point. The Hamwi formula (1964) was designed for clinical nutrition assessment: 48 kg (106 lbs) for women at 5 feet, adding 2.7 kg (6 lbs) per inch above; 52 kg (106 lbs) for men at 5 feet, adding 2.7 kg (6 lbs) per inch above. The Devine formula (1974) was developed for drug dosing calculations. The Robinson formula (1983) and Miller formula (1983) refined earlier estimates using larger population data. All four are reasonable population-level estimates — individual healthy weight depends heavily on body composition, frame size and personal health markers. Use our BMI calculator alongside ideal weight to get a fuller picture and our body fat calculator to assess composition beyond the scale.
| Height | Hamwi (M/F) | Devine (M/F) | Robinson (M/F) | BMI 21.5 (M/F) |
|---|---|---|---|---|
| 5'4" (163cm) | 130/120 lbs | 137/120 lbs | 131/118 lbs | 125/125 lbs |
| 5'7" (170cm) | 148/136 lbs | 155/137 lbs | 148/133 lbs | 138/138 lbs |
| 5'10" (178cm) | 166/152 lbs | 172/154 lbs | 164/149 lbs | 151/151 lbs |
Why Ideal Weight Is Not the Whole Picture
Two people of identical height and weight can have dramatically different health profiles. A 75 kg person with 25% body fat has less muscle mass than a 75 kg person with 15% body fat — despite weighing the same. Muscle is denser and metabolically active; excess body fat, particularly visceral (abdominal) fat, is associated with metabolic disease risk. Body composition assessment — through DEXA scan, hydrostatic weighing, bioelectrical impedance or skinfold measurements — provides far more actionable health information than scale weight alone. Ideal weight formulas also do not account for ethnicity, where cardiovascular risk thresholds for BMI and waist circumference differ between population groups.
Frame Size Adjustment — Small, Medium and Large Frame
Bone structure affects body weight independently of fat and muscle. The most practical way to estimate frame size is wrist circumference. For women over 5'5": wrist under 15.2 cm (6 inches) = small frame, 15.2-15.9 cm = medium frame, over 15.9 cm = large frame. For men over 5'5": wrist under 16.5 cm (6.5 inches) = small frame, 16.5-19 cm = medium frame, over 19 cm = large frame. Standard ideal weight formulas assume medium frame. Adjust downward 10% for small frame and upward 10% for large frame. This adjustment helps explain why two people of identical height may have genuinely different healthy weights based on skeletal structure alone.
| Frame Size | Wrist (Women >5'5") | Wrist (Men >5'5") | Weight Adjustment |
|---|---|---|---|
| Small | Under 6" | Under 6.5" | −10% |
| Medium | 6"–6.25" | 6.5"–7.5" | Baseline |
| Large | Over 6.25" | Over 7.5" | +10% |
Healthy Weight vs Ideal Weight — Understanding the Difference
Ideal weight suggests a single point. Healthy weight is a range — typically the BMI 18.5-24.9 range translated into kilograms or pounds for your height. For a 5'7" (170cm) person, the healthy weight range spans from approximately 53 kg to 80 kg (117-176 lbs) — a 27 kg range. Most people feel and perform best somewhere within this range, but specific optimal point varies by individual body composition, lifestyle and genetics. The focus of weight management should be on sustainable healthy habits — regular physical activity, nutritious eating patterns and adequate sleep — rather than hitting a specific number from a formula developed on population averages.
Using Ideal Weight as a Goal — A Practical Approach
If your current weight is above the calculated ideal range, use the ideal weight as a directional guide rather than an absolute target. Research on long-term weight management consistently shows that aiming for a 5-10% reduction from current weight produces significant health improvements in blood pressure, blood sugar and cholesterol — even without reaching an "ideal" weight. A person at 100 kg who reaches 90 kg gains substantial health benefits regardless of whether 90 kg is their ideal weight by formula. Small, sustained improvements in weight and body composition produce cumulative benefits over time that matter far more than achieving any specific number. Pair ideal weight with regular measurement of waist circumference (a key indicator of visceral fat risk independent of total weight) and fitness markers like resting heart rate and cardiorespiratory endurance for a complete health picture.
Children and Teens — Ideal Weight Works Differently
The ideal weight formulas shown here apply to adults only. For children and teenagers, healthy weight is assessed using age- and sex-specific BMI percentile charts from the CDC or WHO, because body composition changes significantly during growth and development. A BMI percentile at or above the 85th but below the 95th is considered overweight for children; at or above the 95th is obese. Underweight is defined as below the 5th percentile. Paediatric ideal weight assessment should always involve a healthcare provider who can contextualise growth trajectory, puberty timing and developmental stage alongside the numbers. For adults tracking their own weight targets, our ideal weight calculator gives you the four most widely referenced formula results simultaneously so you can see the range rather than a single number, helping you set a realistic and personally appropriate weight goal.
Ultimately, the most useful function of an ideal weight calculator is to give you a concrete, evidence-based starting reference point — not a verdict on your health. Enter your height and sex above to see what four different clinical formulas suggest, use the range to set a directional goal, and focus your energy on the sustainable habits that will get you there rather than on any single number from any single formula.