Calculate ideal body weight using Devine, Robinson, Miller and Hamwi formulas. Includes BMI range, frame size adjustment and over-65 guidance | Calculator4U
Calculate ideal body weight using the Devine Formula.
The Ideal Weight Calculator helps you determine a healthy target weight based on your height and biological gender using four clinically and scientifically validated formulas — Devine, Robinson, Miller, and Hamwi. Originally developed in the 1960s to 1980s for clinical applications such as medication dosing and anesthesia calculations, these ideal body weight (IBW) formulas have become valuable reference points for anyone pursuing optimal health. Understanding your IBW range is essential for setting realistic fitness goals, assessing health risks, and planning effective weight management strategies.
While no single number defines "ideal" for everyone, these evidence-based calculations provide a medically recognized starting point that accounts for physiological differences between men and women. For a 5 foot 8 inch adult, the average of all four formulas gives 150 lbs for men and 140 lbs for women, with a healthy range of plus or minus 10%. Use Calculator4U to compare all four formulas side by side and find your personalized range.
One important limitation to understand: the Devine formula — though the most commonly used in clinical settings — was not derived from systematic research. It was based on estimates from Devine's clinical mentor and tends to underestimate healthy weight for shorter individuals while overestimating for very tall ones. In pounds, it calculates ideal weight as 110.23 plus 5.1 lbs for every inch over 5 feet for men, and 100.3 plus 5.1 lbs per inch for women.
Because no single ideal weight formula is universally the most accurate, using the average of all four formulas alongside your BMI healthy range of 18.5 to 24.9 gives a far more balanced and reliable target than any single number. Furthermore, health guidelines evolve with age; for adults over 65, research suggests a slightly higher BMI of 23 to 27 may be associated with better longevity outcomes and protection against frailty than the standard healthy range.
Devine Formula (1974) — Most Common
Men: IBW = 50 kg + 2.3 kg × (height in inches − 60)
Women: IBW = 45.5 kg + 2.3 kg × (height in inches − 60)
Robinson Formula (1983)
Men: IBW = 52 kg + 1.9 kg × (height in inches − 60)
Women: IBW = 49 kg + 1.7 kg × (height in inches − 60)
Miller Formula (1983)
Men: IBW = 56.2 kg + 1.41 kg × (height in inches − 60)
Women: IBW = 53.1 kg + 1.36 kg × (height in inches − 60)
Hamwi Formula (1964)
Men: IBW = 48 kg + 2.7 kg × (height in inches − 60)
Women: IBW = 45.4 kg + 2.2 kg × (height in inches − 60)
All formulas assume a baseline height of 5 feet (60 inches / 152 cm). The Devine formula is most commonly used in clinical settings for medication dosing, while Robinson and Miller tend to give slightly higher estimates for taller individuals.
This table shows average ideal body weight across all four formulas for common heights:
| Height | Men (kg) | Men (lbs) | Women (kg) | Women (lbs) | Healthy Range (±10%) |
|---|---|---|---|---|---|
| 5'0" (152 cm) | 51.6 | 114 | 48.3 | 106 | ±5-11 lbs |
| 5'2" (157 cm) | 55.7 | 123 | 52.0 | 115 | ±6-12 lbs |
| 5'4" (163 cm) | 59.8 | 132 | 55.7 | 123 | ±6-13 lbs |
| 5'6" (168 cm) | 63.8 | 141 | 59.3 | 131 | ±7-14 lbs |
| 5'8" (173 cm) | 68.2 | 150 | 63.4 | 140 | ±7-15 lbs |
| 5'10" (178 cm) | 73.0 | 161 | 68.5 | 151 | ±8-16 lbs |
| 6'0" (183 cm) | 77.6 | 171 | 73.1 | 161 | ±8-17 lbs |
| 6'2" (188 cm) | 82.2 | 181 | 77.7 | 171 | ±9-18 lbs |
| 6'4" (193 cm) | 86.8 | 191 | 82.3 | 181 | ±9-19 lbs |
Values shown are averages of Devine, Robinson, Miller, and Hamwi formulas. Your healthy range is ±10% of these values.
Ideal weight formulas provide a useful starting point, but they don't account for several critical factors that influence your true healthy weight:
Muscle Mass vs. Fat Mass: A 180 lb person with 15% body fat is healthier than a 160 lb person with 30% body fat. Muscle is denser than fat, so athletes and strength trainers often exceed their "ideal" weight while being in excellent health. Body composition matters more than the number on the scale.
Bone Density: People with larger, denser bones naturally weigh more. This is particularly relevant for athletes and those who've done weight-bearing exercise throughout their lives. DEXA scans can measure bone density accurately.
Age-Related Changes: Metabolism slows approximately 2-3% per decade after age 30. As mentioned, adults over 65 may benefit from slightly higher weights to protect against frailty and maintain energy reserves during illness.
Ethnic Variations: IBW formulas were developed primarily from Caucasian populations. Research shows that optimal BMI and weight ranges may differ by ethnicity—Asian populations may have health risks at lower weights, while some populations may be healthy at higher weights.
Where You Carry Weight: Abdominal fat (visceral fat) is more dangerous than fat stored in hips and thighs. Waist circumference and waist-to-height ratio are often better health indicators than weight alone.
Adjust your ideal weight based on your body frame size using wrist circumference measurements:
| Frame Size | Men's Wrist | Women's Wrist | Weight Adjustment | Physical Characteristics |
|---|---|---|---|---|
| Small Frame | < 6.5" (16.5 cm) | < 6.0" (15.2 cm) | Subtract 10% | Narrow shoulders, small joints, thin wrists/ankles |
| Medium Frame | 6.5" - 7.5" (16.5-19 cm) | 6.0" - 6.25" (15.2-15.9 cm) | Use base calculation | Average proportions, typical bone structure |
| Large Frame | > 7.5" (19 cm) | > 6.25" (15.9 cm) | Add 10% | Broad shoulders, large joints, thick wrists/ankles |
Quick frame size test: Wrap your thumb and middle finger around your wrist at the narrowest point. If they overlap easily, you have a small frame. If they just touch, medium frame. If they don't touch, large frame.
❌ Obsessing over a specific number: Your ideal weight is a range, not a single point. A 5 lb variation day-to-day is normal due to water retention, food intake, and other factors. Focus on staying within your healthy range rather than hitting an exact number.
❌ Ignoring body composition: A 90 kg athlete with 12% body fat is healthier than a sedentary 70 kg person with 30% body fat. The scale doesn't distinguish muscle from fat—use body fat percentage measurements for a complete picture of your health.
❌ Treating formulas as universal truth: Different formulas give different results—Devine may say 66 kg while Hamwi says 70 kg for the same height. Use the average of multiple formulas for a more balanced target.
❌ Applying adult formulas to everyone: These IBW formulas are designed for adults. Children, adolescents, pregnant women, and the elderly have different optimal weight calculations. Consult healthcare providers for these populations.
❌ Setting unrealistic timelines: Safe, sustainable weight change is 0.5-1 kg (1-2 lbs) per week. If you're 15 kg from your ideal, expect 4-6 months of steady progress, not weeks. Rapid weight loss often leads to muscle loss and metabolic slowdown.
❌ Comparing yourself to others: Two people of the same height can have vastly different healthy weights based on frame size, muscle mass, and genetics. Your ideal weight is personal—focus on your own health metrics.
See how the four major formulas calculate ideal body weight differently:
| Formula | Year Developed | Men | Women | Primary Use |
|---|---|---|---|---|
| Devine | 1974 | 68.4 kg (151 lbs) | 63.9 kg (141 lbs) | Medication dosing, most common |
| Robinson | 1983 | 67.2 kg (148 lbs) | 62.6 kg (138 lbs) | Lower increment per inch |
| Miller | 1983 | 67.5 kg (149 lbs) | 63.9 kg (141 lbs) | Higher baseline weight |
| Hamwi | 1964 | 69.6 kg (153 lbs) | 63.0 kg (139 lbs) | Original IBW formula |
| Average | — | 68.2 kg (150 lbs) | 63.4 kg (140 lbs) | Recommended target |
Formula variation: Men ±2.4 kg (5 lbs), Women ±1.3 kg (3 lbs). Using the average provides a more balanced target.
Clinical References & Sources: Devine BJ. Gentamicin therapy. Drug Intell Clin Pharm. 1974;8:650–655. Robinson JD, et al. Determination of ideal body weight for drug dosage calculations. Am J Hosp Pharm. 1983;40:1016–1019. Miller DR, et al. Estimation of lean body weight in elderly. Ann Pharmacother. 1983;17:84–89. Hamwi GJ. Therapy: Changing dietary concepts. Diabetes Mellitus: Diagnosis and Treatment. 1964:73-78. CDC Healthy Weight Guidelines. World Health Organization BMI classification. National Institutes of Health Office of Dietary Supplements. Frame size classifications based on Metropolitan Life Insurance height-weight tables. Calculator validated January 2026.
Ideal weight averages across four formulas for adults: 5 foot 4 — men 132 lbs, women 123 lbs. 5 foot 6 — men 141 lbs, women 131 lbs. 5 foot 8 — men 150 lbs, women 140 lbs. 5 foot 10 — men 161 lbs, women 151 lbs. 6 foot 0 — men 171 lbs, women 161 lbs. These are averages of Devine, Robinson, Miller, and Hamwi formulas. Your healthy range is plus or minus 10%. Adjust up 10% for a large frame, down 10% for a small frame.
Ideal weight calculators provide useful clinical reference points but have notable limitations. The Devine formula — the most used — was not derived from systematic research, and tends to underestimate weight for shorter individuals while overestimating for taller ones. All four formulas were developed from primarily Caucasian populations in the 1960s to 1980s. They do not account for muscle mass, bone density, age, or body composition. Use ideal weight alongside BMI range and body fat percentage for a complete picture. For athletes and muscular individuals, body fat percentage is more meaningful than any IBW formula.
Ideal weight is a single calculated number from clinical formulas like Devine — originally developed for medication dosing. Healthy weight is a range corresponding to BMI 18.5 to 24.9, spanning 15 to 25 pounds for most heights. A 5 foot 7 inch person has an ideal weight of approximately 145 lbs but a healthy BMI range of 121 to 163 lbs. The BMI range is generally more practical for general wellness since it reflects population health outcomes better than any single formula. Use ideal weight as a reference point, not a rigid target.
Ideal weight formulas do not include age as a variable because research found it did not improve accuracy. However for adults over 65, research suggests a slightly higher BMI of 23 to 27 may correlate with better health outcomes and longevity — reflecting the need for energy reserves during illness and protection against frailty. Adults also lose approximately 1.5 to 2 inches in height by age 70, which slightly reduces calculated ideal weight. Consult your doctor for personalized guidance if you are over 65.
Ideal body weight formulas consistently underestimate healthy weight for athletes because they do not account for muscle mass. A 5 foot 10 male powerlifter at 195 lbs with 12% body fat is significantly healthier than a sedentary person at 161 lbs — the Devine ideal — with 28% body fat. Athletes should use ideal weight as a general health baseline only, then set performance weight based on body fat percentage, strength performance, and sport-specific weight class requirements.
Measure your wrist at the narrowest point. For men: small frame is under 6.5 inches, medium is 6.5 to 7.5 inches, large is above 7.5 inches. For women: small is under 6.0 inches, medium is 6.0 to 6.25 inches, large is above 6.25 inches. Quick test: wrap your thumb and middle finger around your wrist. If they overlap you have a small frame, just touching is medium, and not touching is large. Adjust ideal weight by minus 10% for small and plus 10% for large frame.
Use both together. Ideal weight formulas give a single clinical reference number — physicians use Devine for medication dosing and anesthesia. BMI range of 18.5 to 24.9 gives a broader healthy weight corridor based on population health outcomes. The best approach is to aim for a weight within your healthy BMI range that falls near your average formula result. For athletes and muscular individuals, body fat percentage is more meaningful than either ideal weight or BMI alone.