Ideal Weight Ranges by Height and Frame Size
Explore the major ideal body weight formulas (Hamwi, Devine, Robinson, Miller), how frame size factors in, and how to use our ideal weight calculator for a realistic, personalized estimate.
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Use the Ideal Weight Calculator to apply what you learn in this guide.
What Is Ideal Body Weight (IBW)?
Ideal Body Weight (IBW) is a clinically-derived estimate of the body weight associated with optimal health outcomes for a given height and sex. It is used by physicians, pharmacists, and nutritionists to dose medications (which are often weight-sensitive), assess nutritional status, and set realistic weight-management targets.
Unlike BMI, which only compares weight to height, IBW formulas were developed from population health studies and account for the structural difference between male and female bodies. Frame size — the width of your skeleton — adds another layer of personalization beyond these formulas.
Important caveat: IBW is a clinical estimation tool, not a prescriptive target. Athletes, people with high muscle mass, elderly individuals, and growing children will find IBW less applicable than the general population.
The Four Major IBW Formulas
All four formulas are based on the same structure: a base weight for a reference height (5 feet / 60 inches), plus an adjustment per additional inch of height.
Height in this context = Height in inches above 5 feet (60 inches)
Let H = height in inches above 5 feet.
Hamwi Formula (1964)
$$ \text{Male IBW} = 48.0 + 2.7 \times H \text{ (kg)} $$ $$ \text{Female IBW} = 45.5 + 2.2 \times H \text{ (kg)} $$
Devine Formula (1974)
$$ \text{Male IBW} = 50.0 + 2.3 \times H \text{ (kg)} $$ $$ \text{Female IBW} = 45.5 + 2.3 \times H \text{ (kg)} $$
Robinson Formula (1983)
$$ \text{Male IBW} = 52.0 + 1.9 \times H \text{ (kg)} $$ $$ \text{Female IBW} = 49.0 + 1.7 \times H \text{ (kg)} $$
Miller Formula (1983)
$$ \text{Male IBW} = 56.2 + 1.41 \times H \text{ (kg)} $$ $$ \text{Female IBW} = 53.1 + 1.36 \times H \text{ (kg)} $$
Step-by-Step Guide
Step 1: Convert Your Height
Convert your height to inches and subtract 60 (5 feet).
Example: 5'10" male $$ H = (5 \times 12 + 10) - 60 = 70 - 60 = 10 \text{ inches above 5 feet} $$
Step 2: Apply All Four Formulas
| Formula | Calculation | IBW (kg) | IBW (lbs) |
|---|---|---|---|
| Hamwi | 48.0 + (2.7 × 10) | 75.0 kg | 165.3 lbs |
| Devine | 50.0 + (2.3 × 10) | 73.0 kg | 160.9 lbs |
| Robinson | 52.0 + (1.9 × 10) | 71.0 kg | 156.5 lbs |
| Miller | 56.2 + (1.41 × 10) | 70.3 kg | 154.9 lbs |
| Average IBW | 72.3 kg | 159.4 lbs |
A 5'10" male has an IBW range of approximately 155–165 lbs depending on the formula used. Our calculator averages all four for a consensus estimate.
Step 3: Adjust for Frame Size
Frame size shifts the IBW range by approximately ±10%:
| Frame Size | Adjustment |
|---|---|
| Small frame | IBW − 10% |
| Medium frame | IBW (no change) |
| Large frame | IBW + 10% |
For the 5'10" male example:
- Small frame: 159 × 0.90 = 143 lbs
- Medium frame: 159 lbs
- Large frame: 159 × 1.10 = 175 lbs
Step 4: Determine Your Frame Size (Wrist Method)
Wrap your thumb and index finger around your wrist at its narrowest point:
| Result | Frame Size (Men) | Frame Size (Women) |
|---|---|---|
| Fingers overlap | Small | Small |
| Fingers just touch | Medium | Medium |
| Gap between fingers | Large | Large |
A more precise method uses wrist circumference relative to height. For men:
- Height > 5'5": Small < 6.5 in, Medium 6.5–7.5 in, Large > 7.5 in
- Height ≤ 5'5": Small < 5.5 in, Medium 5.5–6.5 in, Large > 6.5 in
IBW vs. BMI Healthy Weight Range
As an alternative, the Healthy BMI range (18.5–24.9) can define a weight range for any height:
$$ \text{Healthy Weight Range} = \text{BMI} \times \text{Height}^2 \text{ (in meters)} $$
For a 5'10" (1.78m) individual: $$ \text{Lower bound} = 18.5 \times (1.78)^2 = 18.5 \times 3.168 = 58.6 \text{ kg (129 lbs)} $$ $$ \text{Upper bound} = 24.9 \times (1.78)^2 = 24.9 \times 3.168 = 78.9 \text{ kg (174 lbs)} $$
The BMI range (129–174 lbs) is broader than the IBW estimates (155–165 lbs), reflecting the limitations of BMI as a population-level tool that doesn't account for body composition.
Key Concepts
| Term | Definition |
|---|---|
| IBW | Ideal Body Weight — clinically-derived weight target for a given height and sex |
| Frame Size | Skeletal structure width; small/medium/large; adjusts IBW ±10% |
| Devine Formula | The most used IBW formula in pharmacological dosing |
| BMI | Body Mass Index; weight ÷ height²; population health screening tool |
| Lean Body Mass | Total body weight minus fat; closely related to IBW calculations |
Frequently Asked Questions
Which IBW formula is the most accurate? The Devine Formula is the most widely used in clinical practice, particularly for medication dosing. However, no single formula is more scientifically validated than the others for general health purposes. The average of all four provides the most balanced estimate.
Should bodybuilders or athletes use IBW? No. IBW formulas do not account for high muscle mass. A competitive powerlifter at 220 lbs and 5'10" with 10% body fat is objectively healthy despite being far above any IBW estimate. Athletes should use body fat percentage and performance metrics, not IBW.
Is IBW the same as my goal weight? Not necessarily. IBW is a clinical reference, not a personal target. Your ideal weight depends on your body composition, fitness level, bone density, and how you feel at a given weight. Use IBW as a starting reference, adjusted for frame size and personal health goals.
Why do men and women have different IBW formulas? Men and women have different skeletal proportions, muscle mass distributions, and body fat baselines. Men typically have denser bones and more muscle mass, leading to a higher IBW for the same height.