What Is an Ideal Weight Calculator?
An ideal weight calculator estimates a healthy target weight for your height and sex. Unlike a single number from a vintage insurance chart, modern tools report a range — because healthy adults naturally vary by frame size, muscle mass, and genetics. Our calculator shows the BMI-based healthy band (18.5 to 24.9), the midpoint of that band, and the Devine formula estimate side by side in kilograms and pounds.
Whether you are setting a weight-loss goal, checking if your current weight falls in a low-risk zone, or comparing clinical formulas, having multiple reference points prevents over-reliance on any one method. The calculator updates instantly when you switch between imperial and metric units or change sex, which adjusts the Devine coefficients. For editorial standards on health content, see our editorial policy.
How to Use This Ideal Weight Calculator
- Select imperial or metric units.
- Choose sex — the Devine formula uses sex-specific constants.
- Enter your height (weight is optional and not required).
- Review the healthy BMI range, midpoint, and Devine estimate in both kg and lb.
- Use the copy button to save results for coaching or medical visits.
BMI Healthy Weight Range Formula
Body mass index is weight in kilograms divided by height in meters squared: BMI = kg / m². Solving for weight at a target BMI gives weight = BMI × height(m)². At BMI 18.5 and 24.9, we produce minimum and maximum healthy weights for your stature. For a 5-foot-10-inch (178 cm) person, height in meters is 1.78, so height squared is about 3.17. Minimum weight ≈ 18.5 × 3.17 ≈ 58.6 kg (129 lb); maximum ≈ 24.9 × 3.17 ≈ 79.0 kg (174 lb).
The CDC — About Adult BMI and WHO — BMI classification use these cutoffs for population screening. They do not account for muscle mass, so athletes may be classified overweight despite low body fat. Pair this range with our BMI calculator to see where your current weight sits on the index.
The Devine Formula
Devine et al. published sex-specific ideal body weight equations in 1974 for clinical dosing. For men: IBW (lb) = 110 + 5.2046 × (height in inches − 60). For women: IBW (lb) = 100.3 + 4.5359 × (height in inches − 60). Only height above 5 feet (60 inches) adds to the base; shorter individuals use the base weight. The formula predates modern obesity trends but remains common in hospital protocols and nutrition research.
Devine often lands near the middle of the BMI healthy band for average heights, but it can fall below or above that band for very tall or short people. Treat it as a historical clinical reference, not a mandate. If your goal is fat loss, also estimate composition with our body fat calculator and plan calories with our calorie calculator and macro calculator.
Setting Realistic Weight Goals
Aiming for the midpoint of the healthy BMI range is reasonable for many adults starting a structured program, but gradual progress matters more than hitting a exact pound value. Losing 5–10% of body weight can improve blood pressure, blood sugar, and joint stress even if you remain above the "ideal" line. Strength training preserves lean mass so that scale loss reflects fat reduction — check BMR changes with our BMR calculator.
Children, pregnant individuals, and people with edema or muscle-wasting conditions need individualized medical guidance; BMI-based ideal weight is not designed for those groups. If you have a history of eating disorders, focus on behaviors and clinical support rather than numeric targets alone.
Frequently Asked Questions
What is ideal weight?▼
Ideal weight is a target body weight associated with lower health risk for a given height and sex. There is no single perfect number — healthy ranges span several pounds or kilograms. This calculator shows a BMI-based healthy range (18.5–24.9) and the Devine formula estimate as reference points, not medical prescriptions.
How is the healthy weight range calculated?▼
We convert your height to meters, square it, and multiply by BMI 18.5 for the minimum and 24.9 for the maximum. That produces the weight span the CDC and WHO commonly associate with normal BMI classification. The midpoint is the average of min and max.
What is the Devine formula?▼
The Devine formula (1974) estimates ideal body weight from height and sex: for men, 110 lb plus 5.2046 lb per inch over 5 feet; for women, 100.3 lb plus 4.5359 lb per inch over 5 feet. Clinicians historically used it for drug dosing and ventilation settings. It is one reference point, not a universal target.
Why doesn't age affect ideal weight here?▼
Standard BMI healthy ranges and the Devine formula use height and sex only. Age influences muscle mass and fat distribution, but population BMI cutoffs do not shift by age in most public health guidelines. Older adults may be healthy slightly above the range if they maintain muscle and metabolic health — discuss individual targets with a clinician.
Ideal weight vs. body fat percentage — which matters more?▼
Scale weight alone cannot distinguish muscle from fat. Ideal weight ranges help set ballpark targets, while body fat percentage describes composition. A muscular athlete may exceed the BMI range yet have low body fat. Use both metrics together: check ideal weight for context and body fat for adiposity.
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