Ideal Weight Calculator
Find your healthy weight by height using all four clinical formulas — Robinson, Miller, Devine, and Hamwi — side by side.
Your Details
Used in formula calculations — formulas differ by sex.
feet
inches
Valid range: 4'0″ to 7'6″ (120–230 cm)
These formulas are clinical references, not diagnoses. They don't account for muscle mass, age, or body composition. Consult your doctor for personalized health guidance.
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All four formula results will appear here instantly.
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What Is Ideal Body Weight?
Ideal body weight (IBW) is a clinically estimated weight that is considered appropriate for a given height and sex. The concept was originally developed not for general wellness, but for a very practical medical reason: calculating drug doses. When a patient's weight is used to determine medication dosage, an extreme deviation from "expected" body weight can lead to over- or under-dosing. IBW formulas provide a normalized reference weight.
Over time, IBW has become a popular general health reference. Most people use it as a simple benchmark: "what should I roughly weigh for my height?" It's easy to calculate and gives an immediate, intuitive number. However, it's important to understand that ideal weight formulas are simplified models — they don't account for body composition, age, ethnicity, or frame size.
This calculator runs all four major clinical IBW formulas simultaneously — Robinson (1983), Miller (1983), Devine (1974), and Hamwi (1964) — and shows you the results side by side, along with the corresponding healthy BMI weight range.
The Four Ideal Weight Formulas Explained
Devine Formula (1974)
Source: B.J. Devine, Drug Intelligence & Clinical Pharmacy
Male: IBW (kg) = 50 + 2.3 × (height in inches − 60)
Female: IBW (kg) = 45.5 + 2.3 × (height in inches − 60)
Most widely used clinically — standard for ICU ventilator tidal volume and drug dosing based on creatinine clearance.
Robinson Formula (1983)
Source: J.D. Robinson, CHEST Journal
Male: IBW (kg) = 52 + 1.9 × (height in inches − 60)
Female: IBW (kg) = 49 + 1.7 × (height in inches − 60)
Developed to update Devine with more recent population data. Slightly higher estimates than Devine for tall individuals.
Miller Formula (1983)
Source: D.R. Miller, Am J Hosp Pharm
Male: IBW (kg) = 56.2 + 1.41 × (height in inches − 60)
Female: IBW (kg) = 53.1 + 1.36 × (height in inches − 60)
Tends to produce higher ideal weight estimates than the other formulas — closer to the middle of the healthy BMI range.
Hamwi Formula (1964)
Source: G.J. Hamwi, Diabetes
Male: IBW (lbs) = 106 + 6 × (height in inches − 60)
Female: IBW (lbs) = 100 + 5 × (height in inches − 60)
The oldest and simplest formula, originally designed for diabetic patients. Works in lbs directly. Still widely referenced in nursing and dietary practice.
Worked Examples
Example 1: Male, 5'10" (178 cm)
| Formula | Result (kg) | Result (lbs) |
|---|---|---|
| Robinson | 52 + 1.9 × 10 = 71.0 | 157 lbs |
| Miller | 56.2 + 1.41 × 10 = 70.3 | 155 lbs |
| Devine | 50 + 2.3 × 10 = 73.0 | 161 lbs |
| Hamwi | (106 + 60) × 0.4536 = 75.3 | 166 lbs |
Consensus average: ~72.4 kg (160 lbs). Healthy BMI range at 5'10": 129–173 lbs.
Example 2: Female, 5'4" (163 cm)
| Formula | Result (lbs) |
|---|---|
| Robinson | 49 + 1.7 × 4 = 55.8 kg → 123 lbs |
| Miller | 53.1 + 1.36 × 4 = 58.5 kg → 129 lbs |
| Devine | 45.5 + 2.3 × 4 = 54.7 kg → 121 lbs |
| Hamwi | (100 + 20) × 0.4536 = 54.4 kg → 120 lbs |
Consensus average: ~55.9 kg (123 lbs). Healthy BMI range at 5'4": 108–145 lbs.
Ideal Weight vs. BMI: What's the Difference?
Both ideal weight and BMI are height-based estimates of healthy weight, but they differ in approach:
| Aspect | Ideal Weight (IBW) | BMI |
|---|---|---|
| Output | Single target weight (kg/lbs) | A range (e.g., 129–173 lbs at 5'10") |
| Formula type | Linear (height only) | Height² based ratio (kg/m²) |
| Accounts for age | No | No |
| Accounts for muscle | No | No |
| Clinical use | Drug dosing, ventilator settings | Population health screening |
| Best used for | Quick reference point | Tracking relative to population norms |
Limitations of Ideal Weight Formulas
No muscle mass consideration
A muscular athlete weighing 210 lbs at 5'10" would be told their ideal weight is ~160 lbs — clearly not meaningful. These formulas assume average body composition.
Developed primarily in European populations
The original formulas were based on data from specific demographic groups. Application to all ethnicities and body types may not be equally appropriate.
Not validated for extremes of height
For very short (under 5'0") or very tall (over 6'4") individuals, linear extrapolation of these formulas produces increasingly inaccurate results.
Age is not factored in
As people age, body composition naturally changes — higher fat percentage at the same weight is common and not necessarily unhealthy. IBW formulas don't account for this.
Sex is binary in these formulas
The formulas use only male/female categories. For intersex, non-binary, or transgender individuals, formulas may be used as approximate references only.
Frequently Asked Questions
About This Calculator
Free ideal weight calculator for men and women. Uses 4 clinical formulas (Robinson, Miller, Devine, Hamwi) to find your ideal body weight by height. Instant results.
Frequently Asked Questions
What is ideal body weight?
Ideal body weight (IBW) is a clinically estimated weight range considered healthy for a given height and sex. Originally developed for medical drug dosing, it is now used as a general health reference.
Why do the four formulas give different results?
Each formula was developed by a different researcher for a slightly different purpose. Robinson (1983) and Miller (1983) for general clinical use. Devine (1974) for drug dosing. Hamwi (1964) for diabetic patients. The average provides a reasonable consensus.
Which ideal weight formula is most accurate?
No single formula is universally most accurate. Devine is most used clinically (drug dosing, ICU ventilation). For general wellness, the average of all four is a sensible reference.
Does ideal weight account for muscle mass?
No. All formulas are based only on height and sex. A muscular athlete may weigh significantly more than their ideal weight without being unhealthy. Body fat percentage is more meaningful for athletes.
Is ideal weight different from healthy BMI weight?
Yes, often slightly. IBW formulas typically fall within the lower half of the healthy BMI range (18.5–24.9). Both are useful references — BMI gives a range, IBW gives a specific target weight.
Sarah brings a public health background to SuperCalc's health and fitness calculators. She translates clinical formulas into accessible tools backed by peer-reviewed research.
- MPH, Columbia University
- Former health data analyst at CDC
- Published health literacy researcher