Knowing your ideal body weight provides a useful reference point for setting realistic health and fitness goals. Our free ideal weight calculator applies four clinically established formulas — Devine, Robinson, Miller, and Hamwi — to estimate a healthy weight range based on your height and gender. Rather than giving you a single number, it shows a range so you can understand the variability across methods and choose a target that makes sense for your body type and lifestyle.
Ideal body weight (IBW) is a clinical estimate of the weight considered healthy for a given height and gender. The concept originated in the 1960s–1980s when researchers developed formulas primarily for pharmaceutical dosing — many medications are prescribed based on IBW rather than actual weight. Over time, these formulas became widely used as general health references. The four main formulas (Devine, Robinson, Miller, Hamwi) each use different coefficients, producing a range of estimates that together give a more complete picture than any single number. It is important to understand that IBW does not account for individual factors like muscle mass, bone density, age, or ethnicity.
Our ideal weight calculator offers: Four formula comparison (Devine, Robinson, Miller, Hamwi) displayed side by side. Support for both metric (kg/cm) and imperial (lb/ft-in) units. Gender-specific calculations reflecting physiological differences. Frame size adjustment guidance. Clear range display showing minimum to maximum IBW across formulas. Educational content explaining each formula's origin and use case. Mobile-responsive design. Complete privacy with client-side processing. No registration or account needed.
When you enter your height and gender, the calculator simultaneously runs all four IBW formulas. Each formula starts with a base weight for someone exactly 5 feet tall, then adds a specific amount per additional inch of height. For example, Devine adds 2.3 kg per inch for men and 2.3 kg for women (with different base values). The results are displayed as a range, with the lowest and highest estimates clearly marked. If frame size adjustment is available, it applies a ±10% modification to each result.
Weight Loss Goal Setting — Provides a science-based target range to aim for rather than arbitrary numbers. Clinical Drug Dosing — Pharmacists use IBW to calculate medication doses for drugs like aminoglycosides and anesthetics. Fitness Planning — Personal trainers reference IBW when designing long-term body composition programs. Nutritional Counseling — Dietitians use IBW to set calorie and protein targets. Health Insurance — Some actuarial models reference IBW ranges. Surgical Planning — Anesthesiologists calculate ventilator settings and drug doses using IBW. Research — Epidemiological studies use IBW for population health analysis.
Our calculator provides multiple formula results simultaneously, giving you a range rather than a single potentially misleading number. This multi-formula approach helps you understand the inherent uncertainty in weight targets. It is completely free, requires no sign-up, and processes everything locally in your browser — your health data is never transmitted or stored. Combined with tools like our BMI Calculator and Body Fat Calculator, it forms part of a comprehensive body composition assessment.
Adults setting weight management goals who want a science-based reference point. Healthcare professionals calculating drug doses or nutritional requirements. Personal trainers and fitness coaches creating client programs. Anyone curious about where their weight falls relative to clinical estimates. People starting a weight loss or gain journey who need a realistic target. Nutritionists planning calorie and macro targets based on ideal weight.
Select your gender and enter your height accurately (measure without shoes against a wall for best results). Review the results from all four formulas and note the range. Consider your frame size — if you have a larger build, aim toward the higher end of the range. Compare your current weight to the IBW range for context, but remember that body composition matters more than hitting an exact number. Use this alongside our BMI and body fat calculators for a complete picture.
Compare All Formulas — Don't rely on a single formula; the range gives better context. Account for Frame Size — Adjust expectations for your bone structure. Consider Muscle Mass — If you strength train regularly, you may healthily exceed IBW. Track Body Composition — Body fat percentage is more meaningful than weight alone. Set Realistic Goals — Aim for the IBW range, not an exact number. Combine Metrics — Use IBW with BMI, waist circumference, and body fat for full assessment. Consult Professionals — Discuss targets with your doctor or dietitian.
IBW formulas were developed decades ago on limited population samples and may not reflect modern body diversity. They do not account for muscle mass, bone density, age, or ethnicity. Athletes and muscular individuals will often exceed IBW while being perfectly healthy. The formulas assume a 'medium' frame unless adjusted. They are not appropriate for children, teens, pregnant women, or elderly individuals. IBW should be used as one reference point among many, not as a definitive health target.
Ideal body weight is a clinically estimated weight range considered healthy for a given height and gender. Originally developed for medication dosing (many drug doses are calculated per kg of IBW), it has become a popular reference for general health. The four main formulas — Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964) — each produce slightly different results. IBW is useful as a rough guideline, but it doesn't account for muscle mass, bone density, or body fat distribution.
Each formula uses height as the primary input. Devine formula for men: 50 + 2.3 kg per inch over 5 feet; for women: 45.5 + 2.3 kg per inch over 5 feet. Robinson for men: 52 + 1.9 kg per inch over 5 feet; for women: 49 + 1.7 kg per inch. Miller for men: 56.2 + 1.41 kg per inch over 5 feet; for women: 53.1 + 1.36 kg per inch. Hamwi for men: 48 + 2.7 kg per inch over 5 feet; for women: 45.5 + 2.2 kg per inch.
No single formula is universally 'most accurate' since they were designed for different clinical purposes. The Devine formula is the most widely used in pharmacology. Robinson and Miller tend to produce higher estimates, which may be more realistic for modern populations. Most practitioners recommend looking at the range across all four formulas rather than relying on one. For a more comprehensive assessment, combine IBW with BMI and body fat percentage.
Yes, significantly. Someone with a large frame (wider wrists, broader shoulders) naturally carries more bone and muscle mass. A common adjustment is ±10% from the calculated IBW: subtract 10% for small frames and add 10% for large frames. You can estimate frame size by measuring wrist circumference — under 6.5 inches for women or 7 inches for men typically indicates a small frame.
Not exactly. Ideal weight formulas give a single point estimate based on height and gender, while 'healthy weight' is a broader range typically defined by a BMI of 18.5–24.9. A muscular person may weigh well above their IBW and still be perfectly healthy. Conversely, someone at their IBW could have high body fat and low muscle. Use IBW as one data point alongside body fat percentage, waist circumference, and fitness level.
Men and women have different body compositions on average. Men typically carry more muscle mass and have denser bones, resulting in higher ideal weights at the same height. Women naturally have higher essential body fat (10–13% vs 2–5% for men). All four major IBW formulas use separate equations for each gender to account for these physiological differences.
No, standard IBW formulas are designed for adults over 18. Children and teens are still growing, so their weight should be evaluated using age-and-sex-specific growth charts (CDC percentiles). Pediatricians track BMI-for-age rather than IBW. If you're concerned about a child's weight, consult their pediatrician for proper assessment.
Your ideal weight based on height doesn't change frequently — only recalculate if your height measurement changes or you want to try a different formula. However, your relationship to that number changes as body composition shifts. Focus on tracking body fat percentage, strength, and how you feel rather than obsessing over a single target number. Reassess your overall health metrics quarterly.