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Ideal Weight Calculator – Devine, Robinson, Miller, Hamwi & BMI Range

Ideal Weight Calculator

The Ideal Weight Calculator estimates your healthy weight range using four common formulas: Devine, Robinson, Miller, and Hamwi. It also provides a BMI‑based healthy weight range (18.5–24.9). Whether you are setting fitness goals, monitoring your health, or simply curious, this tool gives you a personalised target based on your height, gender, and frame size.

Ideal Weight FormulasDevine | Robinson | Miller | HamwiBased on height, gender & frame sizeBMI healthy range: 18.5 – 24.9Frame adjustments: ±10% (small/large)Use as guide – consult a doctor

Ideal Weight Formulas

Devine (1974): Men: 50 + 2.3 kg/in over 5ft; Women: 45.5 + 2.3 kg/in over 5ft.

Robinson (1983): Men: 52 + 1.9 kg/in; Women: 49 + 1.7 kg/in.

Miller (1983): Men: 56.2 + 1.41 kg/in; Women: 53.1 + 1.36 kg/in.

Hamwi (1964): Men: 48 + 2.7 kg/in; Women: 45.5 + 2.2 kg/in.

Frame adjustment: ±10% for small/large frame.

How to Use This Ideal Weight Calculator

  1. Select metric (cm) or imperial (ft/in).
  2. Enter your height.
  3. Choose your gender and frame size.
  4. Click “Calculate” to see multiple ideal weight estimates and your healthy BMI range.

Why Ideal Weight Matters

  • Health monitoring: Staying within a healthy weight range reduces risk of diabetes, heart disease, and joint problems.
  • Fitness goals: Provides a realistic target for weight loss or gain.
  • Medical reference: Doctors use ideal weight formulas for medication dosing and nutritional assessments.
Understanding Ideal Weight – Beyond the Numbers

The concept of ideal weight has evolved over decades. Early tables (like the 1940s Metropolitan Life tables) were based on insurance data linking weight to mortality. Modern ideal weight calculators use formulas that take into account height, gender, and sometimes frame size. However, no single number is perfect for everyone. The BMI healthy weight range (18.5–24.9) is often more flexible and accounts for natural body variations.

Ideal Body Weight Formulas Comparison Reference Table

Formula MethodMale 5′10″ (178 cm)Female 5′5″ (165 cm)Primary Clinical Application
Devine (1974)73.0 kg (160.9 lb)57.0 kg (125.7 lb)Clinical pharmacology & medication dosing standard
Robinson (1983)71.0 kg (156.5 lb)57.5 kg (126.8 lb)Modified empirical scale for general population
Miller (1983)70.3 kg (155.0 lb)59.9 kg (132.1 lb)Higher baseline weighting for females
Hamwi (1964)75.0 kg (165.3 lb)56.5 kg (124.6 lb)Original diabetic dietetics baseline
Healthy BMI (18.5–24.9)58.0 – 78.1 kg50.4 – 67.8 kgWHO global health guideline range

Frame size matters because people with larger bones and broader shoulders naturally weigh more at the same height. To measure your frame, wrap your thumb and middle finger around your wrist. If they overlap, you may have a small frame; if they just touch, medium; if not, large. Our calculator adjusts the formulas by ±10% for small/large frames, giving you a more personalised estimate.

It is important to remember that muscle weighs more than fat. A muscular athlete may have a high BMI and fall outside the “ideal weight” range but be perfectly healthy. Conversely, a person with low muscle mass could be at a normal weight yet have unhealthy body fat. Therefore, use this ideal weight calculator as a starting point. For a complete health picture, consider also measuring waist circumference, body fat percentage, and overall fitness level.

Practical tips: If your current weight is above the ideal range, aim to lose 0.5‑1 kg per week through a combination of diet and exercise. If you are below the range, focus on nutrient‑dense foods and strength training to build muscle. Recalculate your healthy weight target every few months as your body changes. Bookmark this ideal weight calculator to track progress and stay motivated.

Step‑by‑Step Manual Example

Female, 165 cm (5′5″), medium frame:

Devine: 45.5 + 2.3×(65‑60) = 45.5 + 11.5 = 57.0 kg

Robinson: 49 + 1.7×5 = 57.5 kg

Miller: 53.1 + 1.36×5 = 59.9 kg

Hamwi: 45.5 + 2.2×5 = 56.5 kg

Healthy BMI range: 18.5×(1.65²)=50.4 kg to 24.9×(1.65²)=67.8 kg

Frequently Asked Questions about Ideal Weight

What is Ideal Body Weight (IBW)?
Ideal Body Weight (IBW) is a medically calculated target weight based on height, biological sex, and skeletal frame size, originally developed to assist in clinical medication dosing and nutritional requirements.
Which ideal weight formula is considered the medical standard?
The Devine formula (1974) is the most widely recognized formula in clinical pharmacology and critical care medicine for calculating therapeutic drug dosages.
What are the differences between Devine, Robinson, Miller, and Hamwi formulas?
Devine (1974) uses 50 kg (men) / 45.5 kg (women) base. Robinson (1983) uses slightly lower scaling. Miller (1983) uses a higher base weight. Hamwi (1964) uses 48 kg (men) / 45.5 kg (women) base.
How does frame size affect ideal body weight?
Skeletal frame size modifies ideal weight estimates by ±10%: Small frame reduces target by 10%, Medium frame uses baseline, and Large frame increases target by 10%.
How can I measure my body frame size?
Measure wrist circumference: For women, <5.5 in is Small, 5.5–6.0 in is Medium, >6.0 in is Large. For men, <6.5 in is Small, 6.5–7.5 in is Medium, >7.5 in is Large.
Is IBW or healthy BMI range better for fitness tracking?
Healthy BMI range (18.5–24.9 kg/m²) provides a broader, more realistic range of healthy weights, while IBW formulas give precise single-point clinical baselines.
Can athletes rely strictly on ideal weight formulas?
No. Muscular athletes often exceed IBW baselines due to dense lean muscle mass without carrying excess body fat.
Does ideal weight change with age?
Classic IBW formulas do not adjust for age after adulthood, but modest natural weight gain with age is accounted for when evaluating overall health alongside waist-to-hip ratio.