Ideal Weight Calculator
Compare ideal body weight estimates from four widely-used medical formulas: Devine, Robinson, Miller, and Hamwi. Enter your height and gender to see the range and average recommended weight.
"Ideal body weight" (IBW) is a clinical estimate of an individual's healthy weight based primarily on height and sex. Multiple formulas have been developed over the past century for use in medication dosing, surgical planning, nutritional assessment, and general health screening. The most widely used — Devine, Robinson, Miller, and Hamwi — produce slightly different estimates for the same person, with results typically clustered within 5–10 pounds of each other.
It's important to recognize what ideal weight is and isn't. It's a height-based statistical estimate of healthy weight for average body composition. It's NOT a precise target you should hit, and it doesn't account for muscle mass, bone density, or body fat percentage. A muscular athlete may be well above "ideal weight" while having lower body fat than someone at IBW. A sedentary person at IBW may have higher body fat than is healthy. For meaningful body composition assessment, BMI combined with body fat percentage and waist circumference is more informative than IBW alone.
This calculator implements all four standard IBW formulas and shows the range. Use the result as a clinical reference point — particularly useful for medical contexts where IBW affects medication dosing or surgical risk — and as a general weight planning baseline. For most healthy adults, a BMI in the 18.5–24.9 range corresponds roughly to the IBW range. If you're an athlete or have significant muscle mass, body fat percentage is the better measure than IBW.
Inputs
Results
Average Ideal Weight
159 lbs
Devine Formula
161 lbs
Robinson Formula
157 lbs
Miller Formula
155 lbs
Ideal Weight by Formula
Formula
How to use this calculator
- Select your gender. The formulas use different coefficients for men and women, reflecting average differences in body composition.
- Enter your height in feet and inches. The formulas use total height including the base 5 feet and the additional inches.
- Review the four formula estimates and the average. The range is typically 5–10 lbs across formulas.
- Compare to your current weight to see whether you're above, within, or below the typical IBW range.
- Use the result as a clinical reference, not a personal weight goal. The "ideal" weight depends on individual body composition, activity level, and health goals — not just height.
- For more meaningful body composition assessment, also use the BMI calculator (height-weight ratio), body fat calculator (composition assessment), and TDEE calculator (calorie needs based on activity level).
- Healthy weight range is typically considered ±10% of IBW or BMI 18.5–24.9 — there's no single "ideal" number for individuals.
Worked examples
Adult female, 5'5"
Female, 5'5" (5 inches above 5 feet). Devine: 45.5 + 2.3 × 5 = 57 kg = 126 lbs Robinson: 49 + 1.7 × 5 = 57.5 kg = 127 lbs Miller: 53.1 + 1.36 × 5 = 59.9 kg = 132 lbs Hamwi: 45.5 + 2.2 × 5 = 56.5 kg = 125 lbs Average: 57.7 kg = 127 lbs Range (±10%): 114 to 140 lbs For comparison: BMI 22 at 5'5" = 132 lbs. The IBW formulas closely align with healthy BMI ranges.
Tall adult male, 6'4"
Male, 6'4" (16 inches above 5 feet). Devine: 50 + 2.3 × 16 = 86.8 kg = 191 lbs Robinson: 52 + 1.9 × 16 = 82.4 kg = 182 lbs Miller: 56.2 + 1.41 × 16 = 78.8 kg = 174 lbs Hamwi: 48 + 2.7 × 16 = 91.2 kg = 201 lbs Average: 84.8 kg = 187 lbs Range (±10%): 168 to 206 lbs The four formulas spread more for tall individuals (28-lb range). Hamwi tends to overestimate; Miller tends to underestimate. Clinical use typically averages multiple formulas.
Lifter — ideal weight doesn't apply
Male, 5'10", weight 210 lbs, 13% body fat, regular lifter. IBW formulas suggest: ~155-165 lbs healthy weight range. But this person has dramatically more muscle than the formulas assume. At 13% body fat, his lean mass is 183 lbs (210 × 0.87). The IBW estimate is 30+ lbs below his actual healthy weight given his body composition. For athletic populations, body fat percentage is the better health metric than IBW. The lifter's lean-mass-heavy physique is a healthy outcome that IBW formulas fail to recognize.
When to use this calculator
Use this calculator as a general reference for healthy weight ranges, when starting a weight management program, or when evaluating clinical recommendations from healthcare providers. The IBW formulas are widely used in medical contexts for medication dosing, nutritional assessment, and pre-surgical planning — knowing your IBW can help you understand healthcare provider recommendations.
For weight loss or maintenance goals, IBW is a starting reference but shouldn't be the only metric. More informative measures:
1. **BMI (Body Mass Index).** Height and weight ratio; the standard public health screening tool. Healthy range 18.5–24.9 corresponds roughly to IBW range. BMI doesn't distinguish muscle from fat, so it overestimates risk for muscular individuals and may underestimate for low-muscle individuals.
2. **Body fat percentage.** Best assessment of body composition. Healthy ranges: 10–20% men, 18–28% women. More expensive/complex to measure precisely than weight, but cheap Navy-tape methods give reasonable estimates.
3. **Waist circumference.** Indicates visceral fat (the dangerous type). Healthy thresholds: under 40" for men, under 35" for women. A meaningful health indicator independent of body weight.
4. **Waist-to-height ratio.** Waist divided by height, target under 0.5. Simple and surprisingly informative.
Pair this with the BMI calculator, body fat calculator, BMR calculator, TDEE calculator, calorie calculator, and macro calculator for a complete body composition and nutrition planning suite.
A note on the formulas' history: the Devine formula was originally developed (in 1974) for medication dosing in renal patients, where IBW was used as an alternative to actual body weight for calculating dose. The other formulas were developed for similar clinical contexts. They were never intended as fitness or weight loss targets — that's a usage that grew organically. Their popularity for general health screening is a side effect of clinical adoption.
For most healthy adults seeking a "target weight," the BMI range 22–24 (middle of healthy range) is a defensible starting point, refined by body fat percentage assessment if available. Don't fixate on a single "ideal weight" number — sustainable healthy ranges, not pinpoint targets, are what produce long-term outcomes.
Common mistakes to avoid
- Treating IBW as a precise personal target. The formulas are population averages — your individual healthy weight depends on body composition, muscle mass, and activity level. A 10-lb range around the average is reasonable.
- Ignoring body composition. A muscular person well above IBW may be healthier than a sedentary person at IBW. IBW measures only height-weight relationship.
- Using IBW alone for medication dosing without context. Modern clinical dosing often uses adjusted body weight or actual body weight depending on the drug and the patient. IBW is one input, not a sole determinant.
- Crash dieting to reach IBW. Aggressive weight loss to hit an arbitrary number often backfires through metabolic adaptation and rebound weight gain. Sustainable rate is 0.5–1 lb per week through modest calorie deficit and activity.
- Applying IBW formulas to children. The formulas were developed for adults. Pediatric weight assessment uses different standards (BMI percentiles for age and sex).
- Confusing "ideal" with "average." IBW is a clinical estimate of healthy weight, not what the average person actually weighs. U.S. average adult weight is significantly higher than IBW for most age groups due to widespread overweight/obesity.
Frequently Asked Questions
Sources & further reading
- Body Weight Standards — clinical guidance — U.S. Centers for Disease Control and Prevention
- Healthy Weight, Nutrition, and Physical Activity — U.S. Centers for Disease Control and Prevention
- Dietary Guidelines for Americans 2020-2025 — U.S. Department of Agriculture / U.S. Department of Health and Human Services