Which ideal weight formula is most accurate?

No single formula is universally most accurate. The Devine formula is the most widely used in clinical settings, particularly for drug dosing. The Robinson and Miller formulas were developed to refine Devine's estimates. Using the average of all four provides a more balanced estimate than any single formula alone.

Why do the four formulas give different results?

Each formula was developed using different study populations, methodologies, and time periods (1964-1983). Hamwi's formula tends to give higher estimates for taller individuals, while Miller's tends to give higher baseline weights. The differences reflect varying assumptions about healthy body composition.

Should I aim for my calculated ideal weight?

Ideal body weight formulas provide a general reference, not a personal prescription. Your optimal weight depends on many factors including muscle mass, bone density, body composition, fitness level, and overall health. Use IBW as a starting point and consult a healthcare provider for personalized guidance.

Does frame size affect ideal body weight?

Yes, body frame size significantly impacts what a healthy weight looks like. These formulas do not account for frame size differences. A person with a large frame may be perfectly healthy at a weight above their calculated IBW, while someone with a small frame may be healthiest slightly below it.

How does muscle mass affect ideal body weight calculations?

Muscle is denser than fat, so muscular individuals often weigh more than their calculated IBW while being in excellent health. These formulas were designed for average body compositions and do not account for above-average muscle mass. Athletes and strength trainers should consider body composition metrics like FFMI instead.

Free Ideal Body Weight Calculator

Estimate your ideal body weight using four established medical formulas based on your height and gender.

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Enter your height and gender to estimate your ideal body weight

What is Ideal Body Weight?

Ideal body weight (IBW) is an estimated weight that is considered healthy for a person based on their height and gender. It is widely used in clinical settings for medication dosing, nutritional assessments, and setting general health goals. IBW formulas provide a reference point rather than a definitive target.

This calculator uses four of the most established medical formulas to estimate your ideal body weight, giving you a range of values and an overall average. Comparing results across formulas provides a more balanced picture than relying on any single estimate.

The Four Formulas

Devine (1974) - The most widely used formula, originally developed for calculating drug dosages.

Male: 50 + 2.3 x (height in inches - 60) kg

Female: 45.5 + 2.3 x (height in inches - 60) kg

Robinson (1983) - A refinement of the Devine formula using updated population data.

Male: 52 + 1.9 x (height in inches - 60) kg

Female: 49 + 1.7 x (height in inches - 60) kg

Miller (1983) - Tends to estimate slightly higher baseline weights than other formulas.

Male: 56.2 + 1.41 x (height in inches - 60) kg

Female: 53.1 + 1.36 x (height in inches - 60) kg

Hamwi (1964) - One of the earliest IBW formulas, still commonly referenced.

Male: 48 + 2.7 x (height in inches - 60) kg

Female: 45.5 + 2.2 x (height in inches - 60) kg

Why Results Differ Between Formulas

Each formula was developed using different study populations and methodologies across different decades (1964-1983). The Devine and Hamwi formulas tend to produce more divergent results for taller individuals because they use larger per-inch multipliers. The Robinson and Miller formulas generally produce estimates that are closer together. The average of all four provides a reasonable middle ground.

Limitations

Does not account for muscle mass or body composition

Does not consider body frame size (small, medium, large)

Formulas were developed using limited population samples and may not apply equally to all ethnic groups

Less reliable for individuals shorter than 5 feet (152 cm)

Does not factor in age, activity level, or overall health status

Important: Ideal body weight is a general guideline, not a personal health prescription. For a more complete picture of your body composition, consider using our BMI Calculator, FFMI Calculator, or Body Fat Calculator alongside this tool.

Medical Disclaimer

This ideal body weight calculator is for informational and educational purposes only. Results should not replace professional medical advice, diagnosis, or treatment. Ideal weight estimates are population-based approximations and may not reflect your individual health needs.

When to Consult a Healthcare Provider

Always consult with qualified healthcare professionals for personalized weight management guidance, especially if you have concerns about your weight, are managing a medical condition, or are considering significant dietary or lifestyle changes.

Free Ideal Body Weight Calculator

What is Ideal Body Weight?

The Four Formulas

Why Results Differ Between Formulas

Limitations

Medical Disclaimer

When to Consult a Healthcare Provider

Frequently Asked Questions

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