Ideal Weight Calculator
Calculate your ideal weight using 6 scientific formulas: Lorentz, Devine, Robinson, Miller, Hamwi, Creff.
Your information
Determines your body frame for the Creff formula. Male: < 16 cm = small, 16-18 = medium, > 18 = large
Everything about ideal weight calculation
Why calculate your ideal weight?
There's no single ideal weight. Different scientific formulas give different estimates based on varying criteria: height, sex, body frame. Comparing 6 formulas gives you a more reliable overview than a single number.
Our calculator compares Lorentz, Devine, Robinson, Miller, Hamwi, and Creff formulas in one table. The Creff formula accounts for your body frame (small, medium, large), making it more personalized.
Free and confidential: no data is sent to any server. All calculations run in your browser.
Who uses this calculator?
- Individuals
- Get a realistic ideal weight range by comparing multiple scientific formulas rather than a single number.
- Healthcare professionals
- Use as a quick reference tool during consultations to discuss weight goals with patients.
- Fitness coaches
- Estimate clients' target weight range to set realistic and healthy goals.
- Nutrition students
- Compare different ideal weight formulas and understand their assumptions and limitations.
How to use the calculator
Enter your height, sex, age, and select your body frame (small, medium, or large) for the Creff formula.
The calculator instantly displays results from all 6 formulas in a clear comparison table.
Check the recommended weight range and the formula average for a balanced estimate.
Frequently asked questions
- Which ideal weight formula is best?
- No formula is perfect. Lorentz is simplest but ignores age. Creff is most comprehensive as it includes age and body frame. In practice, averaging multiple formulas gives the most reliable estimate.
- What's the difference between ideal weight and normal BMI?
- BMI defines a normal weight range (18.5-24.9 kg/m²), while ideal weight formulas calculate a single target weight based on height and other criteria. Both approaches complement each other.
- How does the Lorentz formula work?
- Lorentz calculates ideal weight based on height and sex. For men: Weight = Height(cm) - 100 - (Height - 150) / 4. For women: Weight = Height(cm) - 100 - (Height - 150) / 2.5. It's simple but doesn't account for age or body frame.
- Does body frame really affect ideal weight?
- Yes. A large-framed person will naturally have a higher ideal weight than a small-framed person of the same height. The Creff formula is the only one among the six that factors this in using coefficients of 0.9 (small), 1.0 (medium), or 1.1 (large).
- Is my data confidential?
- Yes. No personal data is transmitted or stored. All calculations run locally in your browser.
Understanding ideal weight formulas
What are the main ideal weight formulas?
The most used formulas are: Lorentz (1929, based on height and sex), Devine (1974, originally for drug dosing), Robinson (1983, Devine revision), Miller (1983, lighter results), Hamwi (1964, used in American dietetics), and Creff (includes age and body frame). Each has its assumptions and limitations.
How has the concept of ideal weight evolved?
The concept has evolved significantly. Early weight tables from insurance companies (Metropolitan Life, 1940s) aimed to predict mortality. Modern formulas focus more on optimal health. Today, experts prefer 'healthy weight range' over a single ideal weight, as health depends on many factors beyond weight alone.
Why do ideal weight formulas give different results?
Each formula was developed in a different context with different populations. Devine's formula was created to calculate gentamicin dosages, not to define healthy weight. The differences illustrate that no absolute ideal weight exists and the concept is relative to chosen criteria.