Which ideal weight formula is most accurate — Devine, Robinson, Miller, or Hamwi?
No formula is universally best. The Devine formula (1974) is most widely used in clinical settings (e.g., for medication dosing). Robinson (1983) and Miller (1983) are slight revisions. Hamwi (1964) is common in dietetic practice. All four are based on height-only and were derived from small studies — they are rough estimates, not targets. Body composition matters far more than a number on a scale.
What is the ideal weight for my height?
As a rough guide using the Devine formula: for a 5'7" (170 cm) woman, ideal weight ≈ 61 kg (134 lbs); for a 5'10" (178 cm) man ≈ 72 kg (159 lbs). These figures assume a medium frame and average body composition. Athletic individuals naturally weigh more due to muscle mass, while fine-boned individuals may be healthy at the lower end.
Is there such a thing as an "ideal" body weight?
The concept of a single ideal weight is outdated. Health depends far more on body composition (muscle vs fat), fitness level, metabolic health markers (blood pressure, blood sugar, cholesterol), and lifestyle than on a scale number. A person at their "ideal weight" per formula can still be metabolically unhealthy (skinny-fat), while someone above it can be metabolically excellent.
How is ideal weight different from a healthy BMI weight range?
Ideal weight formulas give a single target number; healthy BMI weight gives a range (18.5–24.9 BMI). For a 1.70 m woman, the healthy BMI range is 53.5–72.0 kg — a 18.5 kg span. The formula's ideal weight typically falls mid-range. Both approaches are simple estimates that ignore muscle mass, bone density, and individual variation.
How do I use ideal body weight for medication dosing?
The Devine formula was originally developed to calculate appropriate medication doses (particularly renally-cleared drugs and those with narrow therapeutic windows) based on the weight at which organs function normally — not actual body weight. If you are significantly heavier than your IBW, some drugs are dosed on IBW (e.g., certain antibiotics, anaesthetics) to avoid toxicity. Always follow your prescriber's guidance.