Ideal Weight Calculator
Calculate your ideal body weight based on different scientific formulas.
Ideal Weight Formulas Compared
There is no single 'ideal' weight — each formula answers a different question. Devine was built for drug dosing, Robinson and Miller adjusted it after observing that Devine overestimates for taller people. The BMI-based range is what mainstream medicine currently uses because it is height-based and population-validated.
Frame size, muscle mass, and age shift the healthy range by 10-15% in either direction. An athlete with high lean mass can be 'overweight' by BMI while perfectly healthy; an older adult may be healthiest slightly above the BMI range (sarcopenia protection).
Worked Example: Woman, 5 ft 6 in (66 in)
Devine: 45.5 + 2.3 × (66 − 60) = 45.5 + 13.8 = 59.3 kg (≈ 130.7 lb)
Robinson: 49 + 1.7 × 6 = 59.2 kg — consistent
BMI healthy range: 1.6764 m² × 18.5–24.9 = 52.0–69.9 kg (115–154 lb)
The formulas agree near the middle of the healthy BMI band
Notice the healthy range spans nearly 18 kg — 'ideal' is a band, not a number. Aim for the weight where energy, labs, and strength are good, then keep it stable.
Frequently Asked Questions
Which ideal weight formula is most accurate?
None is universally 'accurate' — they estimate. The BMI range (18.5-24.9) has the strongest population evidence; Devine/Robinson/Miller matter clinically for dosing (creatinine clearance, chemotherapy). Use BMI as the primary target and formulas for context.
Does ideal weight change with age?
Body composition shifts: lean mass declines ~3-8% per decade after 30. Many geriatric guidelines suggest a slightly higher BMI (23-28) for adults 65+ is protective — the 'ideal' of your 20s is not the ideal of your 70s.
How does frame size affect the number?
Wrist circumference estimates frame: a small-framed person may be healthy 10% below the mid-band, a broad-framed person 10% above. That is why two people the same height can both be healthy at very different weights.
Is ideal weight the same as goal weight for weight loss?
Not necessarily. Research shows losing just 5-10% of body weight already improves blood pressure, lipids, and blood sugar. Set the first goal there rather than at a formula number.
Authoritative Sources & Further Reading
Last reviewed: September 2026. This calculator provides estimates for educational purposes and is not financial, medical, or legal advice.
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