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Ideal Weight Calculator Online — Calculate Healthy Weight Range Free

Find your ideal weight range using 4 trusted medical formulas: Devine, Robinson, Miller, and Hamwi. Enter your height and gender to see results instantly. Supports metric and imperial units. No upload, no sign-up.

Free Ideal Weight Calculator — Find Your Healthy Weight Range

OptiDrop's Ideal Weight Calculator uses four well-established medical formulas to estimate your ideal body weight based on your height and gender. Rather than relying on a single formula, this calculator shows results from Devine, Robinson, Miller, and Hamwi methods, along with their average, giving you a comprehensive healthy weight range to aim for.

Understanding the Four Formulas

Each formula was developed independently by medical researchers. The Devine formula (1974) is the most commonly used, originally designed for drug dosage calculations. The Robinson formula (1983) was developed as a refinement of Devine's work. The Miller formula (1983) provides slightly different estimates. The Hamwi formula (1964) is one of the oldest methods, often used in clinical settings. By comparing all four, you get a more reliable weight range than any single formula provides.

Metric and Imperial Support

Switch between metric (centimeters) and imperial (feet and inches) units at any time. All calculations happen instantly in your browser. No data is uploaded or stored. Your ideal weight results are private and calculated entirely on your device.

Frequently Asked Questions

Your ideal weight is a healthy weight range based on your height and gender. It is calculated using medical formulas such as Devine, Robinson, Miller, and Hamwi. These formulas provide a range rather than a single number because healthy weight varies between individuals based on body composition, frame size, and muscle mass.
Ideal weight is calculated using mathematical formulas that take your height and gender as inputs. Each formula uses different coefficients. For example, the Devine formula starts at a base weight and adds a fixed amount per inch of height above 5 feet. This calculator shows results from 4 formulas and their average for a well-rounded estimate.
The Devine formula (1974) is one of the most widely used ideal body weight formulas. For men: 50 kg + 2.3 kg per inch over 5 feet. For women: 45.5 kg + 2.3 kg per inch over 5 feet. Originally designed for calculating medication dosages, it has become a standard reference for ideal body weight estimation.
A healthy weight for your height falls within the range provided by ideal weight formulas, typically corresponding to a BMI between 18.5 and 24.9. This calculator shows the average ideal weight from four medical formulas. However, factors like muscle mass, bone density, age, and overall health should also be considered. Consult a healthcare professional for personalized advice.

Last updated: June 2026