Ideal weight calculator
Compare Devine, Robinson, Miller and Hamwi with adult BMI boundaries, without prescribing a target.
Fill in the fields and the result will appear here automatically.
Compares four historical reference-weight equations: Devine (1974), Robinson and Miller (1983), and Hamwi (1964). They use height and published sex-specific constants, without body composition, illness or personal goals. Their average is a comparison statistic; their spread is not a confidence interval. Separate weight boundaries for BMI 18.5 and 25 describe an adult screening category for ages 20 and over. Neither this interval nor a point equation confirms health or sets a desired weight.
How it works
Formula and logic
x = height/2.54 − 60 inches. Men: Devine 50+2.3 x; Robinson 52+1.9 x; Miller 56.2+1.41 x kg; Hamwi (106+6 x) lb. Women: 45.5+2.3 x; 49+1.7 x; 53.1+1.36 x kg; (100+5 x) lb. 1 lb =0.45359237 kg. Average = sum/4. With h in metres, BMI interval: 18.5 h² ≤ weight <25 h².
Example
A man at 180 cm: Devine 74.992 kg, Miller 71.521 kg, Hamwi 77.654 kg; average 74.203 kg. BMI boundaries are 59.94 kg included and 81 kg excluded. Heights below 152.4 cm receive an applicability error rather than a constant weight.
Fields and units
- Sex — list option
- Height — cm
How to use
- — Choose the published sex-specific constant set.
- — Enter 152.4–230 cm; these equations are used here from five feet.
- — Compare methods without turning the average into a weight-loss plan.
- — Read the upper BMI boundary as excluded: weight must be below it.
Method and limitations
- Calculation method
- Formula and logic
- Data or methodology source
- Peterson et al. (2016): Table 3, historical weight equations CDC: adult BMI categories, ages 20+
- Limitation
- Reference-equation comparison, not a personal target, diagnosis or dosage. BMI boundaries are for adults 20 and over, not child or pregnancy standards.
FAQ
Which reference-weight result should be my target?
None automatically. Averaging four historical estimates does not create a personal recommendation. This tool compares methods and does not calculate treatment targets or medicine doses.
Why do BMI boundaries differ from reference-weight equations?
BMI produces an interval using height squared; the named equations produce individual linear points. At 180 cm, 81 kg is BMI 25 and is outside the stated interval.
Do these weight equations account for muscle?
No. Height and constants do not measure body composition. High muscle mass can explain disagreement but cannot by itself establish health.
Why do reference equations offer two sex sets?
Those are their published constant sets. The choice selects coefficients rather than assessing an individual’s identity or physiology; there is no third validated set here.
How does this comparison differ from ordinary BMI?
Ordinary BMI uses actual weight. This tool derives weights from height. Children, pregnancy and treatment require other assessment methods; equal height does not mean equal needs.