Advertisement

⚖️ Ideal Weight Calculator

Find height-based ideal body weight from Devine, Robinson, Miller, and Hamwi formulas, plus the healthy BMI weight range for your height.

Height-Based Ideal Weight Ranges — Multiple Formulas

BrainyCalculators editorial insight — unique to this tool

Robinson, Miller, Devine, and Hamwi formulas differ by ±5 kg for same height — a 5'10" man ranges ~68–78 kg depending on formula. Frame size (wrist circumference) adjusts Broca index. These are population heuristics from insurance era, not personalized body-composition targets.

When to use this calculator

Use for rough healthy weight band by height. For current fat assessment, use BMI or Lean Body Mass.

Need body composition instead of target weight?

This page estimates height-based ideal weight. To estimate lean mass, fat mass, and protein targets from body composition formulas, use the Lean Body Mass Calculator →

cm ft/in

What is Ideal Body Weight (IBW)?

Ideal Body Weight (IBW) is a height-based reference weight originally developed for clinical dosing and nutrition assessment. It is not a direct body-fat measurement and it is not meant to be a single mandatory target for every person at a given height.

This calculator compares Devine, Robinson, Miller, and Hamwi formulas and shows the healthy BMI range for the same height. Use it when you need a clinical reference weight, a broad weight-management target, or a range to discuss with a healthcare professional.

If you want to separate fat mass from lean tissue, use the Lean Body Mass Calculator. If you want a quick weight-status category based only on height and weight, use the BMI Calculator.

The Four Formulas

Devine (1974)
Male: 50 + 2.3 × (inches over 5ft) kg
Female: 45.5 + 2.3 × (inches over 5ft) kg
Robinson (1983)
Male: 52 + 1.9 × (inches over 5ft) kg
Female: 49 + 1.7 × (inches over 5ft) kg
Miller (1983)
Male: 56.2 + 1.41 × (inches over 5ft) kg
Female: 53.1 + 1.36 × (inches over 5ft) kg
Hamwi (1964)
Male: 48 + 2.7 × (inches over 5ft) kg
Female: 45.5 + 2.2 × (inches over 5ft) kg

How to Use This Calculator

  1. 1
    Select Your Gender
    All four ideal weight formulas use separate equations for males and females.
  2. 2
    Enter Your Height
    Use the toggle to switch between cm and ft/in. The formulas are based on height in inches above 5 feet.
  3. 3
    Compare All Formulas
    See results from all four formulas side by side, plus the healthy BMI weight range for your height.
  4. 4
    Use the Average
    The average of all four formulas is shown as the main result and is a good general target range.

Real-World Example

Male, 175 cm (5ft 9in = 9 inches over 5ft):

Devine = 50 + 2.3 × 9 = 70.7 kg
Robinson = 52 + 1.9 × 9 = 69.1 kg
Miller = 56.2 + 1.41 × 9 = 68.9 kg
Hamwi = 48 + 2.7 × 9 = 72.3 kg
Average = 70.3 kg

How the Ideal Weight Calculator Works

Formula, assumptions, and calculation steps for this health tool.

Methodology

Health calculators use published screening formulas and common planning rules to estimate body, nutrition, pregnancy, or fitness metrics from user inputs.

Calculation Steps

  1. Enter the personal measurements requested by the tool.
  2. Convert height, weight, age, dates, or activity inputs to standard units.
  3. Apply the health or fitness formula for the selected metric.
  4. Show the estimate with practical ranges or interpretation where available.

Assumptions and Limits

  • Results are educational estimates, not diagnosis or medical advice.
  • Individual factors such as medication, pregnancy, and medical history can change interpretation.
  • Consult a clinician for personal health decisions.

Reference basis: Common public-health and sports-science screening formulas.

Frequently Asked Questions

Ideal body weight (IBW) is an estimated weight target associated with good health outcomes for a given height. It was originally developed for drug dosing purposes but is widely used in nutrition and fitness as a general health target.

No single formula is universally most accurate. The Devine formula is the most widely used in clinical settings. The average of all four formulas is generally the best general-purpose estimate. Individual factors like muscle mass, bone density, and body composition are not captured by any formula.

People with larger bone frames naturally weigh more at the same height. A quick assessment: wrap your thumb and middle finger around your wrist — if they overlap you have a small frame; if they just touch, medium; if they do not touch, large frame. Add or subtract 10% from ideal weight for large or small frames.

Not exactly. The formula-based ideal weights and the BMI healthy range (18.5–24.9) often overlap but are not identical. BMI-based healthy weight is a range, while the formulas give a single point estimate. Both are useful references, but neither accounts for muscle mass or body composition.

Real-World Applications

💊
Clinical Drug Dosing
Weight-based drug doses for antibiotics, chemotherapy, and anaesthetics are calculated using ideal body weight (IBW) rather than actual weight to avoid over-dosing in obese patients.
🏋️
Fitness Goal Setting
Use the healthy weight range (from BMI 18.5–24.9) as a scientifically supported target weight range for personal fitness and weight management goals.
🩺
Obesity Assessment
Calculate the percentage above ideal body weight to categorise overweight (>10%), obese (>20%), and morbidly obese (>100% or >50 kg above IBW) for clinical risk stratification.
🏃
Athletic Performance
Combat sport athletes use ideal weight formulas to identify their natural weight class and plan safe, sustainable weight management around competition.
📊
Life Insurance Underwriting
Insurers compare actual weight to ideal weight tables when underwriting life and health policies — significant deviation from IBW can result in premium loading.
🧑‍⚕️
Nutritional Assessment
Dietitians use percentage of ideal body weight (%IBW) to classify nutritional status: 90–110% is normal, 80–90% mild undernutrition, below 70% severe undernutrition.

Common Mistakes

1
Treating IBW as a single precise target
No single formula for ideal body weight is universally validated. Each formula (Devine, Hamwi, Robinson, Miller) gives a slightly different result — use a range rather than obsessing over any one number.
2
Ignoring frame size
Ideal weight formulas based on height alone don't account for skeletal frame size. A person with a large frame may healthily weigh 10–15% more than the formula suggests; a small frame may warrant 10% less.
3
Using IBW for drug dosing in severely obese patients
For morbidly obese patients, some medications use adjusted body weight (ABW = IBW + 0.4 × (actual weight − IBW)) rather than IBW alone — using raw IBW can underdose.
4
Applying adult IBW formulas to children and adolescents
The Devine, Hamwi, and Robinson formulas were developed for adults. For children, use CDC BMI-for-age growth charts which provide percentile-based healthy weight ranges adjusted for age and sex.
5
Confusing healthy weight range with optimal performance weight
Athletes may perform best at a weight outside the standard healthy range — an Olympic weightlifter or rugby prop may be "overweight" by BMI standards but have very low body fat. Performance and health metrics diverge for elite athletes.

IBW Formula Comparison for 5′10″ (178 cm) Male

Formula IBW (kg) IBW (lbs) Developed For
Devine (1974) 72.7 kg 160.3 lbs Drug dosing (clinical)
Hamwi (1964) 78.0 kg 172.0 lbs Endocrinology patients
Robinson (1983) 73.9 kg 163.0 lbs General population
Miller (1983) 71.7 kg 158.1 lbs General population
BMI 22 (mid-range) 70.1 kg 154.5 lbs Population health baseline

References

  1. Devine, B.J. "Gentamicin Therapy." Drug Intelligence and Clinical Pharmacy, 1974.
  2. Hamwi, G.J. "Therapy: Changing dietary concepts." Diabetes Mellitus: Diagnosis and Treatment, 1964.
  3. Robinson, J.D. et al. "Estimating body weight in patients with hepatic disease." Journal of Parenteral and Enteral Nutrition, 1983.
  4. WHO Expert Consultation. "Appropriate Body-Mass Index for Asian Populations." The Lancet, 2004.
  5. Pai, M.P. and Paloucek, F.P. "The origin of the 'ideal' body weight equations." Annals of Pharmacotherapy, 2000.