Ideal Weight Calculator (Lorenz)

Ideal weight from your height and sex

Reviewed by the Nutricity editorial teamLast updated:
Calculator

How it's calculated (Lorenz formula)

The Lorenz formula estimates ideal weight from height and sex:

  • Men: ideal weight = (height − 100) − (height − 150) / 4
  • Women: ideal weight = (height − 100) − (height − 150) / 2

Height is in centimetres and the result is in kilograms. The formula does not account for age or body frame.

How to interpret the result

The result is a single reference weight in kg, not a range. Compare it with your current weight: small differences fall within normal individual variation. For a fuller assessment of weight status, also use your BMI.

Why it matters

"Ideal weight" is one of the most searched calculations: it serves as a reference for weight goals, for estimating needs when a person cannot be weighed, and in some clinical contexts.

Compare the result with the Metropolitan Life tables and with your body mass index.

How to measure your height

  • Measure height barefoot, with your back straight and gaze horizontal.
  • Enter the value in centimetres.
  • Select your sex, which sets the coefficient used by the formula.

What to do about your result

Treat the value as a rough reference, not a rigid target: a "healthy" weight also depends on muscle mass, bone structure and age.

When to see a professional: to set realistic and safe weight goals, consult a doctor or dietitian.

Limitations of the formula

  • It ignores age, body frame and body composition.
  • It is a historical, approximate method: different formulas give different results.
  • It is not suitable for children, athletes or specific clinical situations.

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Frequently asked questions

How does the Lorenz formula work?
It estimates the ideal weight from height and sex, without taking the person's age or body frame into account.
How accurate is it?
It is fairly approximate precisely because it ignores age and body frame. It remains useful as a quick estimate when the patient cannot be weighed directly.
What is the difference between ideal weight and BMI?
BMI assesses current weight status relative to height, whereas the Lorenz formula proposes a reference "ideal" weight value.
Does the result replace a medical assessment?
No, it is an informational estimate. For personalised weight goals consult a healthcare professional.

Sources

  1. Pai MP, Paloucek FP. The origin of the "ideal" body weight equations. Ann Pharmacother. 2000;34(9):1066-1069.
  2. World Health Organization. Obesity and overweight (fact sheet). 2024.
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