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Ideal Weight Calculator

Three evidence-based formulas side by side. Devine, Robinson, Miller — in kg and lb.

cm
kg

⚠️ These formulas were developed for clinical use and do not account for body composition, ethnicity, or activity level. They serve as reference points, not absolute targets.

About the three formulas

All three formulas were developed for clinical use — primarily to estimate drug dosing based on ideal body weight, not as fitness targets. They're based on height and sex, ignoring muscle mass, bone density, and body frame size.

  • Devine (1974): The oldest and most commonly used in clinical settings for drug dosing.
  • Robinson (1983): Slightly higher estimates than Devine, developed to address some limitations.
  • Miller (1983): Generally gives the highest values, tends to be closest to BMI-based healthy weight ranges for taller individuals.

Ideal Weight Formulas Compared

Each formula produces a single number based on height and sex — using a linear equation anchored at 5 feet (60 inches) in the imperial system.

  • Devine (1974): Men = 50 + 2.3 × (height in inches − 60); Women = 45.5 + 2.3 × (height in inches − 60). The original clinical formula, developed for pharmacological drug dosing and kidney function estimation — not fitness targets.
  • Robinson (1983): Men = 52 + 1.9 × (height in inches − 60); Women = 49 + 1.7 × (height in inches − 60). Slightly higher estimates for men, very close to Devine for women — developed to address limitations of the original model.
  • Miller (1983): Men = 56.2 + 1.41 × (height in inches − 60); Women = 53.1 + 1.36 × (height in inches − 60). Produces the highest results overall, and tends to be closest to healthy BMI ranges for taller individuals.

All three are linear approximations — they systematically underestimate ideal weight for tall people and overestimate it for short people. A more flexible modern approach: use the healthy BMI range (18.5–24.9 applied to your height) to derive a weight range rather than a single fixed number.

Related tools: BMR Calculator, Body Fat Calculator, Lean Body Mass Calculator, and Calorie Calculator.

Limitations of 'Ideal Weight'

These formulas were designed for pharmacological dosing — estimating kidney clearance and medication amounts in hospital settings. Applying them as personal fitness targets has no scientific basis.

  • Body composition is ignored: A muscular athlete can weigh 20 kg above their Devine ideal weight while having excellent metabolic health. The formula cannot distinguish between fat mass and lean mass.
  • Ethnicity and bone structure: Asian populations face higher metabolic health risks at lower BMIs, leading WHO to recommend a lower healthy BMI threshold (18.5–23) for these groups. African and Caribbean populations may be systematically underclassified as overweight by standard formulas.
  • Age and muscle loss: Sarcopenia (muscle loss with aging) means the same scale weight reflects much less lean mass at 65 than at 25. An older adult "at ideal weight" may carry more visceral fat than the number suggests.
  • A more complete picture: Clinicians increasingly combine BMI 18.5–24.9 with waist circumference thresholds (under 94 cm for men, under 80 cm for women) and body fat percentage to assess health risk — not a single target weight from a 1974 formula.

Frequently Asked Questions

What is my ideal body weight?
'Ideal weight' depends on which formula you use and what goal you're targeting. Clinical formulas (Devine, Robinson, Miller) give a reference range based on height and sex. For most purposes, a weight that keeps your BMI between 18.5–24.9 and your body fat in a healthy range is a better personal target than any single formula.
Why do the three formulas give different results?
Each formula was derived from a different patient population using different statistical methods. Robinson and Miller corrected perceived limitations in Devine's original work. Since they use different coefficients, the results diverge more for people who are significantly taller or shorter than average.
Should I target the ideal weight shown by these formulas?
Not necessarily. These formulas were created for clinical dosing, not fitness goals. They don't account for body composition — a muscular person would be told they're 'overweight' while actually being healthier than their formula suggests. Use these as one reference point among several, alongside BMI, body fat percentage, and how you feel and perform.
Which ideal weight formula is most accurate?
No single formula is 'most accurate' because ideal weight depends on body composition, not just height and sex. The Devine formula is the most widely cited in clinical settings (used for drug dosing). For health and fitness goals, a healthy BMI range (18.5–24.9 for most adults, or 18.5–23 for Asian populations per WHO) paired with body fat percentage is a more meaningful target.
Can I weigh more than my 'ideal' weight and still be healthy?
Yes — Athletes, people with high muscle mass, or those with larger bone frames routinely fall above formula estimates while having excellent metabolic health markers (blood pressure, cholesterol, blood sugar, waist circumference). Conversely, a person at their 'ideal' formula weight can have elevated visceral fat and poor health outcomes. Use these numbers as rough reference points, not rigid targets.
Should I aim to reach my ideal weight?
These formulas provide a rough reference, not a health mandate. Body composition, muscle mass, bone density, and fitness level matter more than a single number. Consult a healthcare professional to set realistic, personalized goals.

⚠ Ideal weight formulas (Devine 1974, Robinson 1983, Miller 1983, Hamwi 1964) were developed as clinical dosing guides, not universal health standards. These are estimates. Consult a healthcare professional for personalized advice.

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By Bam's Thinkery — Updated

Informational tool. Not a substitute for advice from a qualified healthcare professional.