Free Ideal Weight Calculator
Find your ideal body weight using four proven medical formulas. Free calculator shows Hamwi, Devine, Robinson, and Miller results for your height and gender.
Ideal Weight Range
154 – 166 lbs
based on 4 medical formulas
Hamwi
166 lbs
Devine
161 lbs
Robinson
157 lbs
Miller
154 lbs
These are general estimates based on height and gender. Individual ideal weight varies based on body frame, muscle mass, and other factors. Consult a healthcare provider for personalized guidance.
Formula
Hamwi (Male): 106 + 6×(inches over 5ft) | Devine (Male): 110.23 + 5.07×(inches over 5ft) | Robinson (Male): 115.13 + 4.19×(inches over 5ft) | Miller (Male): 123.46 + 3.09×(inches over 5ft)What Is Ideal Body Weight?
Ideal body weight (IBW) is an estimated weight range associated with the lowest risk of weight-related health problems for a given height and gender. Unlike BMI, which provides a single ratio, ideal weight formulas give you a specific target weight in pounds or kilograms. These formulas have been used in clinical medicine for decades to guide drug dosing, nutritional planning, and health assessments.
Our calculator uses four of the most widely recognized formulas: Hamwi (1964), Devine (1974), Robinson (1983), and Miller (1983). Each was developed from different population data, which is why they produce slightly different results. Viewing all four together gives you the most balanced estimate.
The Four Formulas Explained
- Hamwi Formula (1964): One of the earliest and simplest. Uses a base weight for 5 feet plus a fixed increment per additional inch. Tends to produce moderate estimates.
- Devine Formula (1974): Originally developed for calculating drug dosages, this became the most commonly used formula in clinical practice. It's the basis for many online calculators.
- Robinson Formula (1983): A refinement of the Devine formula using updated population data. Generally produces values close to Devine but with slightly different increments.
- Miller Formula (1983): Tends to produce the highest estimates, particularly for taller individuals. Uses the smallest per-inch increment, resulting in a higher base weight.
Factors Beyond the Formulas
While these formulas provide useful reference points, your true ideal weight depends on many factors they don't account for:
- Body frame size — people with larger bone structures naturally weigh more
- Muscle mass — muscle is denser than fat, so athletic individuals may weigh more at the same height
- Age — body composition changes with age, and healthy weight ranges shift accordingly
- Overall health markers — blood pressure, cholesterol, blood sugar, and fitness level matter more than a number on the scale
Use these results as a general guide, and work with a healthcare provider to determine the best weight goal for your individual circumstances.
Frequently Asked Questions
Which ideal weight formula is most accurate?
No single formula is universally 'most accurate.' The Devine formula is widely used in clinical settings, while the Robinson and Miller formulas tend to give slightly higher estimates. Using all four gives you a reasonable range. Your ideal weight also depends on muscle mass, body frame, and overall health.
Why does this calculator require a minimum height of 5 feet?
These formulas were developed using data from adults 5 feet (60 inches) and taller. Below that height, the linear extrapolation becomes unreliable. For shorter individuals, BMI-based ranges or consultation with a healthcare provider may be more appropriate.
Should I aim for the lowest or highest number in the range?
Neither specifically. The range represents different medical estimates. Where you fall within it depends on your body frame (small, medium, large), muscle mass, and individual health factors. A medium-framed person might aim for the middle, while a large-framed or muscular person might be healthy at the higher end.
How does gender affect ideal weight?
Men typically have more muscle mass and denser bones than women, which is why the male formulas produce higher ideal weights at the same height. These are population averages — individual variation is significant. Athletes and people with above-average muscle mass may have healthy weights above these ranges.
Is ideal weight the same as healthy weight?
Not necessarily. 'Ideal weight' formulas provide general targets based on height and gender, but 'healthy weight' is individual. Factors like muscle mass, bone density, body fat distribution, fitness level, and medical history all matter. Use these numbers as a starting reference point, not an absolute goal.