Ideal Weight Calculator

Calculate your ideal body weight using 5 proven medical formulas

Your Ideal Weight Range
BMI equivalent:
Formula Comparison
Formula Breakdown

Height–Weight Reference Table

How Is Ideal Body Weight Calculated?

Ideal body weight (IBW) formulas estimate a healthy target weight based on height and gender. Clinicians have used these formulas since the 1960s for drug dosing, nutritional assessment, and ventilator settings. While no single number defines "ideal," using multiple formulas gives you a realistic range for your height.

Devine Formula (1974)

The most widely used formula in medicine. Originally developed by Dr. B.J. Devine for calculating drug dosages, not as a health target. It tends to underestimate ideal weight for shorter individuals and overestimate for taller ones.

  • Male: 50 + 2.3 kg per inch over 5 ft
  • Female: 45.5 + 2.3 kg per inch over 5 ft

Robinson Formula (1983)

Dr. Robinson updated the Devine formula with improved population data, producing more moderate estimates that better reflect real-world body weights.

  • Male: 52 + 1.9 kg per inch over 5 ft
  • Female: 49 + 1.7 kg per inch over 5 ft

Miller Formula (1983)

Dr. Miller's formula tends to produce the highest ideal weight estimates, making it more lenient than other formulas. Some experts consider it the most realistic for modern populations.

  • Male: 56.2 + 1.41 kg per inch over 5 ft
  • Female: 53.1 + 1.36 kg per inch over 5 ft

Hamwi Formula (1964)

The oldest of the group, developed by Dr. G.J. Hamwi. It's commonly used by dietitians as a quick reference for initial weight assessments.

  • Male: 48 + 2.7 kg per inch over 5 ft
  • Female: 45.5 + 2.2 kg per inch over 5 ft

BMI-Based Range

Rather than a single number, the BMI-based method calculates the weight range corresponding to a healthy BMI of 18.5–24.9. This provides the widest reference range and accounts for individual variation.

Which Formula Is Most Accurate?

No single formula is definitively "best." Research suggests the Robinson and Miller formulas align most closely with modern population data, while the Devine formula remains the clinical standard for drug dosing. The BMI-based range is most useful as a general health reference because it acknowledges that healthy weight is a range, not a single number.

For the most complete picture, look at the range across all formulas rather than picking one. If all five formulas agree your ideal weight is between 65–72 kg, you can be confident that range is reasonable for your height.

Limitations of Ideal Weight Formulas

  • No body composition data: These formulas don't account for muscle mass, bone density, or body fat percentage. A muscular athlete may weigh well above their "ideal" weight and be perfectly healthy.
  • Based on older populations: Most formulas were developed using data from the mid-20th century, which may not reflect current demographics.
  • Height baseline: All four classic formulas use 5 feet as a baseline, making them less reliable for very short (<5 ft) or very tall (>6'4") individuals.
  • No age adjustment: Healthy weight tends to increase slightly with age, but these formulas don't account for that.
  • Binary gender model: The formulas only provide male and female calculations, which may not suit everyone.

Frequently Asked Questions

No single formula is universally most accurate. The Devine formula is the most widely used in clinical settings, but the Robinson and Miller formulas tend to give more realistic ranges for modern populations. Using all five formulas together gives you a reliable range rather than a single number.
BMI is a ratio of weight to height squared and classifies you into categories (underweight, normal, overweight, obese). Ideal body weight formulas give you a specific target weight in pounds or kilograms based on your height, gender, and sometimes frame size. BMI doesn't account for gender or frame size.
Yes. People with larger bone structures naturally weigh more at the same height. A large-framed person's ideal weight is typically 10% higher than a medium-framed person, while a small-framed person's ideal weight is about 10% lower. You can estimate frame size by measuring your wrist circumference relative to your height.
Each formula was developed using different population data and methodologies. Devine (1974) was originally for drug dosing, Robinson (1983) updated it with better data, Miller (1983) tends to allow higher weights, and Hamwi (1964) is the oldest. The differences reflect varying assumptions about body composition.
All four classic formulas (Devine, Robinson, Miller, Hamwi) use 5 feet (152.4 cm) as the baseline height. They start with a base weight for someone who is 5 feet tall and then add a specific amount per additional inch of height. This is why these formulas may be less accurate for very short or very tall individuals.
No. Ideal weight calculators provide a reference point, not a strict target. A healthy weight depends on many factors including muscle mass, body fat percentage, age, and overall fitness level. Use the calculated range as a general guide and consult a healthcare professional for personalized advice.

Related Tools