Ideal Body Weight Calculator
Classic IBW formulas from height — dosing/reference sketches, not a body-image target. Click any i for detail.
IBW
Sex
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Sex
Formula constants differ by sex. |
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Height (in)
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Height
Height in inches (5′6″ = 66). |
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Formula
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Formula
Devine is the most common clinical teaching default. |
How to use this calculator
- Select sex and formula.
- Enter height in inches.
- Read IBW in kg and lb.
Results explained
Ideal body weight formulas were built for clinical dosing and population reference, not as a personal “should weigh” mandate. Devine is the most widely taught: male 50 kg + 2.3 kg per inch over 5′, female 45.5 kg + 2.3 kg per inch over 5′. Robinson and Miller use slightly different slopes. Healthy weight ranges also depend on muscle, bone, and medical context — BMI and clinician judgment still matter.
Quick reference: IBW formulas
All start at 5′ (60 in) and add kg per extra inch.
| Item | Detail |
|---|---|
| Devine male | 50 + 2.3×(in−60) |
| Devine female | 45.5 + 2.3×(in−60) |
| Robinson | Slightly different intercepts/slopes |
| Miller | Another common variant |
Educational reference — not a prescription for weight loss or gain.
How the estimate is built
IBW_kg = base + slope×max(height_in − 60, 0) (Devine/Robinson/Miller constants).
Example scenario
Female, 66 in, Devine → about 59.3 kg (131 lb).
FAQ
Is IBW the same as a healthy weight?
Not necessarily. Athletes and people with higher muscle mass may sit above IBW and still be healthy. Use clinical context.
Why do hospitals use IBW?
Many drug-dosing and ventilation teaching examples scale to IBW or adjusted body weight. Follow your formulary.
What if I am under 5 feet?
These formulas are least reliable below 60 in. Ask a clinician for pediatric or short-stature guidance.
Should I aim for this number on the scale?
Not by default. Treat it as a reference sketch, not a vanity target.