CalcPro

Ideal Weight Calculator

Ideal body weight by four classic formulas, plus a healthy range.

Not medical advice. This tool is for general information and education only. It is not a diagnosis and cannot replace a doctor. Consult a qualified healthcare professional before acting on any result.

How it works

This calculator applies four classic formulas to estimate your ideal body weight based on your height and gender. Each formula produces a slightly different result; together they define a realistic healthy range rather than a single target.

The four methods—Devine, Robinson, Miller, and Hamwi—were developed between 1964 and 1983 and remain standard references in clinical nutrition and fitness assessment. They all follow the same pattern: a base weight plus an adjustment for every inch (or centimetre) above a reference height.

The formula

Devine: 50 kg (110 lb) + 2.3 kg (5 lb) per inch over 5'0" for women; 50 kg (110 lb) + 2.3 kg (5 lb) per inch over 5'0" for men (adjusted to 45.5 kg / 100 lb for women)

Robinson, Miller, and Hamwi use similar structures with different base weights and per-inch multipliers. The calculator computes all four and displays the results alongside your BMI-based healthy weight range (18.5–24.9 BMI).

Worked example

Let's calculate the ideal weight for a woman who is 5'6" (167.6 cm) tall.

Devine formula:

  • Base for women: 45.5 kg (100 lb)
  • Height above 5'0": 6 inches
  • Per-inch adjustment: 2.3 kg (5 lb)
  • Calculation: 45.5 + (6 × 2.3) = 45.5 + 13.8 = 59.3 kg (130.6 lb)

Robinson formula:

  • Base: 49 kg (108 lb)
  • Per-inch adjustment: 1.7 kg (3.75 lb)
  • Calculation: 49 + (6 × 1.7) = 49 + 10.2 = 59.2 kg (130.4 lb)

Miller formula:

  • Base: 53.1 kg (117 lb)
  • Per-inch adjustment: 1.36 kg (3 lb)
  • Calculation: 53.1 + (6 × 1.36) = 53.1 + 8.16 = 61.26 kg (135 lb)

Hamwi formula:

  • Base: 45.4 kg (100 lb)
  • Per-inch adjustment: 2.27 kg (5 lb)
  • Calculation: 45.4 + (6 × 2.27) = 45.4 + 13.62 = 59.0 kg (130 lb)

The four estimates cluster around 59–61 kg (130–135 lb). Her BMI-based healthy range (18.5–24.9) at 5'6" spans roughly 50–64 kg (110–141 lb). The formula estimates sit comfortably within this broader range.

Common mistakes

Treating the result as a prescription. These formulas are population averages. A person with significant muscle mass may healthily weigh 5–10 kg more; someone with a smaller frame may weigh less. Genetics, age, fitness level, and body composition all matter.

Ignoring the healthy range. The BMI-based range is deliberately wider than any single formula because healthy bodies come in different shapes. If you're within the range and feel strong and energetic, you're likely in a good place.

Forgetting this is an estimate, not professional advice. If you're planning significant weight changes, especially for health reasons, speak with a doctor or registered dietitian who can assess your individual circumstances.

This calculator provides estimates for general information only, not medical or dietary advice.

Frequently asked questions

What's the difference between these four formulas?

Each formula was developed by different researchers and uses slightly different coefficients. Devine (1974) is the most widely cited in clinical practice. Robinson (1983) tends to give slightly lower estimates. Miller (1983) and Hamwi (1964) fall between them. Using all four gives you a realistic range rather than a single number.

Is ideal weight the same as healthy weight?

Not exactly. Ideal weight is a calculated target based on height and gender. Healthy weight is a broader range (usually defined by BMI 18.5–24.9) that accounts for individual variation in muscle, bone density, and body composition. This calculator shows both.

Why does gender matter?

On average, men have greater muscle mass and bone density than women at the same height. All four formulas include gender-specific adjustments to reflect these physiological differences.

Should I aim for the exact number?

No. These are estimates, not professional medical advice. Your ideal weight depends on age, fitness level, muscle mass, and overall health. Consult a doctor or registered dietitian for a personalized target.

What if my result seems too high or too low?

Remember that formulas are population averages. If you're very muscular, you may naturally weigh more. If you have a smaller frame, you may weigh less. The healthy range is wider than any single formula suggests.

Can I use this for children?

No. These formulas apply only to adults. Children's ideal weight varies dramatically by age and development stage and requires different assessment methods.

Related calculators

Healthy Weight CalculatorThe weight range for a healthy BMI (18.5–24.9) at your height.BMI CalculatorBody Mass Index and weight category from height and weight.Body Fat CalculatorBody fat percentage using the U.S. Navy circumference method.Lean Body Mass CalculatorLean mass and fat mass using the Boer formula.