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Ideal Weight Calculator Calculate ideal body weight using Robinson, Miller, Devine, and Hamwi formulas plus BMI range.

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Ideal Weight Calculator

Calculate ideal body weight using Robinson, Miller, Devine, and Hamwi formulas plus BMI range.

1

Choose Units & Sex

Select metric or imperial and biological sex.

2

Enter Your Height

Input your height in cm or feet/inches.

3

View Ideal Weight

See results from four formulas and your healthy BMI weight range.

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What Is Ideal Weight Calculator?

The Ideal Weight Calculator provides ideal body weight estimates using four well-known medical formulas: Robinson (1983), Miller (1983), Devine (1974), and Hamwi (1964). Each formula was developed from population data and provides a slightly different estimate, giving you a range of values. The calculator also shows the BMI-based healthy weight range (BMI 18.5-24.9) for your height. No single formula defines a perfect weight — these are reference ranges that help you understand what is statistically associated with good health outcomes for your height and sex.

Why Use Ideal Weight Calculator?

  • Compares four scientifically established ideal weight formulas
  • Shows BMI-based healthy weight range for additional context
  • Supports both metric and imperial measurements
  • Provides a range rather than a single number for realistic expectations

Common Use Cases

Goal Setting

Establish realistic weight goals based on scientific formulas.

Clinical Reference

Healthcare providers use ideal body weight for medication dosing.

Fitness Planning

Understand your target weight range for fitness programs.

Nutrition Assessment

Use as a reference point for calorie and nutrition planning.

Technical Guide

The formulas are based on height in inches over 60 inches (5 feet): Robinson (1983): Men: 52 + 1.9 × (height − 60 in), Women: 49 + 1.7 × (height − 60 in). Miller (1983): Men: 56.2 + 1.41 × (height − 60 in), Women: 53.1 + 1.36 × (height − 60 in). Devine (1974): Men: 50 + 2.3 × (height − 60 in), Women: 45.5 + 2.3 × (height − 60 in). Hamwi (1964): Men: 48 + 2.7 × (height − 60 in), Women: 45.5 + 2.2 × (height − 60 in). All results are in kg. The BMI range is calculated as weight = BMI × height(m)² for BMI values 18.5 and 24.9.

Tips & Best Practices

  • 1
    Treat these as reference ranges, not absolute targets — body composition matters more
  • 2
    The Devine formula is most commonly used in clinical settings for drug dosing
  • 3
    Frame size (small, medium, large) can shift your ideal weight within the range
  • 4
    Focus on body composition and health markers rather than a single number on the scale

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Frequently Asked Questions

Q Which ideal weight formula is best?
No single formula is definitively best. The Robinson formula is often considered most accurate for general populations. The BMI-based range provides the widest, most inclusive healthy range.
Q Why do the formulas give different results?
Each formula was developed from different population studies at different times. They use different coefficients, reflecting the natural variation in what constitutes a healthy weight.
Q Is ideal weight the same as healthy weight?
Not exactly. Ideal weight formulas provide estimates based on height. Healthy weight depends on many factors including body composition, fitness, age, and medical history.
Q Does frame size matter?
Yes, larger-framed individuals may have a higher ideal weight. Add 10% for large frames and subtract 10% for small frames as a rough adjustment.
Q Should I try to reach my ideal weight?
Use ideal weight as a general guideline. Focus on general health markers (blood pressure, blood sugar, cholesterol) and body composition rather than a specific number.

About This Tool

Ideal Weight Calculator is a free online tool by FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration or installation required.