Ideal Weight Calculator
Find your ideal body weight using Devine, Robinson, Miller, and Hamwi formulas — plus a healthy BMI weight range.
Your Details
Enter your height and click Calculate.
How Does the Formula Work?
The ideal weight calculator estimates your target body weight using four widely-cited clinical formulas — Devine, Robinson, Miller, and Hamwi — plus a healthy weight range derived from BMI. Each formula takes only height and sex as inputs, producing a single-point estimate in kilograms. Since no formula is definitive, the calculator shows all four results alongside their average, giving you a range rather than a single number. The BMI-based range (18.5–24.9) provides additional context from the World Health Organization classification.
Robinson (1983): Male = 52 + 1.9 × (height_in − 60) | Female = 49 + 1.7 × (height_in − 60)
Miller (1983): Male = 56.2 + 1.41 × (height_in − 60) | Female = 53.1 + 1.36 × (height_in − 60)
Hamwi (1964): Male = 48 + 2.7 × (height_in − 60) | Female = 45.5 + 2.2 × (height_in − 60)
BMI Range: 18.5 × height(m)² to 24.9 × height(m)²
All four formulas share the same structure: a base weight for someone who is 5 feet (60 inches) tall, plus an increment for each inch above that baseline. The difference lies in the base and increment values, which reflect different study populations and methodologies. Devine's formula, originally developed for drug dosing, became the default "ideal weight" in medical practice. Robinson refined it with updated population data. Miller produces slightly higher estimates. Hamwi, the oldest, gives the widest range between short and tall individuals.
Understanding the Results
For someone 5'10" (70 inches / 178 cm) male, the four formulas produce: Devine 73 kg (161 lb), Robinson 71 kg (157 lb), Miller 70.3 kg (155 lb), Hamwi 75 kg (165 lb). The spread is about 5 kg (11 lb) — a normal variation. The BMI-based healthy range for the same height is 58.8–80.4 kg (130–177 lb), much wider. Use the formula average as a central reference and the BMI range as the boundaries of healthy weight.
Why Multiple Formulas Matter
No single ideal weight formula accounts for body composition, frame size, muscle mass, or ethnic variation. A person with a large frame and significant muscle mass may be healthy 10–15 lb above their Devine ideal. Conversely, a small-framed sedentary person might be healthy at or below the Robinson estimate. Showing all four formulas plus the BMI range lets you see the uncertainty built into any "ideal weight" estimate. The range itself is more valuable than any single number.
Limitations
These formulas were developed from data on American and European adults in the mid-20th century. They may not be appropriate for individuals of Asian, African, or other ethnic backgrounds without adjustment. They do not account for age (ideal weight shifts slightly with aging), pregnancy, or medical conditions. Athletes, bodybuilders, and people with above-average muscle mass will consistently exceed formula estimates — for them, body fat percentage (measured by DEXA or skinfold calipers) is a better metric than scale weight. The CDC and NIH recommend using BMI alongside waist circumference and clinical risk factors for a complete health assessment.
These formulas provide statistical estimates only and are not a substitute for professional medical advice. Ideal weight varies based on body composition, muscle mass, bone density, age, and medical history. Always consult a qualified healthcare provider for personalized weight assessment.
The Four Formulas Compared
This calculator uses four established medical formulas that each approach ideal weight differently. The Devine formula (1974) is the most widely used in clinical settings for drug dosing — it starts at a base weight for 5 feet and adds a fixed amount per inch. The Robinson formula (1983) produces slightly lower estimates than Devine and is often considered more accurate for women. The Miller formula (1983) gives the highest estimates, particularly for shorter individuals. The Hamwi formula (1964) is the oldest and simplest. All four formulas assume a medium frame — actual ideal weight varies by bone structure, muscle mass, and body composition.
Healthy BMI Range
In addition to the four formulas, the calculator shows the healthy weight range based on BMI. A BMI of 18.5 to 24.9 defines the normal weight range. For a person 5 feet 10 inches (178 cm) tall, the healthy weight range is approximately 129 to 174 pounds (58 to 79 kg). This range is intentionally wide because healthy body composition varies significantly — an athletic person with high muscle mass may weigh more than a sedentary person of the same height yet have lower body fat and better health outcomes. Use the BMI range as guardrails and the formula results as general targets, not as absolute numbers.
Limitations and Context
Ideal weight formulas were developed decades ago using limited population samples and do not account for ethnicity, age, muscle mass, or bone density. A 25-year-old competitive swimmer and a 65-year-old retiree of the same height have very different body compositions and nutritional needs. The formulas also assume binary gender categories and may not fully apply to all individuals. Waist circumference, body fat percentage, waist-to-height ratio, and overall fitness level are arguably better indicators of health than weight alone. These formulas remain popular because they require only height and gender as inputs — making them quick screening tools, not diagnostic instruments. Always consult a healthcare provider for personalized weight management advice.
Using the Results
The four formulas typically produce results within a 10 to 15 pound range of each other. If three or four formulas agree closely, that range is a reasonable target. If you are significantly above or below this range, discuss it with your doctor before making dietary changes. Rapid weight loss (more than 2 pounds per week) can cause muscle loss, nutritional deficiencies, and gallstones. Gradual lifestyle changes — balanced nutrition, regular physical activity, adequate sleep, and stress management — produce the most sustainable results. Pair this calculator with our Calorie Calculator for daily energy targets and our BMI Calculator for ongoing monitoring.
Tips & Recommendations
The spread between formulas is intentional. Treat the range as your target zone rather than fixating on a single number.
If you strength train regularly, you may weigh 10–20 lb above formula ideals and still have a healthy body fat percentage.
The BMI range (18.5–24.9) is the WHO standard. If your current weight falls within it, you are in the healthy zone regardless of formula results.
Ideal weight is one data point. Your doctor can assess body composition, blood work, and fitness level for a complete picture.
Frequently Asked Questions
Which ideal weight formula is the most accurate?
No single formula is definitive. Devine is the most widely used in clinical settings, Robinson is considered better for women, and the BMI-based range gives the broadest healthy window. Use the average of all four as a reasonable target — and consult your doctor.
Why do the formulas give different numbers?
Each formula was derived from different study populations and years (1964–1983). They agree closely for average-height adults but diverge at extremes. The spread itself is informative — it shows the range of reasonable weights.
Is ideal weight the same as healthy weight?
Not necessarily. Ideal weight formulas estimate a statistical norm based on height and sex. A muscular athlete may weigh 20 lb above their Devine ideal and still be perfectly healthy. Body composition matters more than the number on the scale.
Do these formulas work for all heights?
They were designed for adults over 5 feet (60 inches / 152 cm). Below that height, the formulas produce unreliable results. Children and teens should use age-specific growth charts.
How should I use this result?
Treat it as a reference range, not a prescription. Compare your current weight to the range, discuss with your healthcare provider, and set goals based on your complete health picture — including blood work, fitness level, and medical history.
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