Ideal Body Weight Calculator - Calculate Your Healthy Weight Range

Calculate your ideal body weight using the Devine, Robinson, Miller, or Hamwi formulas based on your height and gender for health and fitness planning

Updated: August 2025 • Free Tool

Ideal Body Weight Calculator

Your Ideal Weight Results

Devine Formula
72.5 kg
Robinson Formula 70.2 kg
Miller Formula 71.8 kg
Hamwi Formula 73.1 kg
Healthy Range 63.3 - 81.6 kg

What is Ideal Body Weight?

Ideal Body Weight (IBW) is a calculated weight range that is considered optimal for a person's height and gender. Originally developed for medical purposes like drug dosing, IBW is now commonly used as a general health reference.

IBW represents:

  • A weight associated with maximum life expectancy
  • Minimal risk of weight-related health problems
  • A reference point for medical treatments and procedures
  • A guideline for nutritional and fitness planning

How Ideal Body Weight Calculator Works

We use four established formulas to calculate IBW:

Devine Formula (1974):

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

Robinson Formula (1983):

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

Miller Formula (1983):

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

Hamwi Formula (1964):

Male: 48.0 kg + 2.7 kg per inch over 5 feet
Female: 45.5 kg + 2.2 kg per inch over 5 feet

Understanding IBW Formulas

Devine Formula

Most widely used, originally for drug dosing calculations.

Robinson Formula

Based on data from the Metropolitan Life Insurance Company.

How to Use This IBW Calculator

1

Choose Units

Select metric (kg/cm) or imperial (lbs/in) units

2

Enter Height

Input your height accurately in the selected units

3

Select Gender

Choose your gender for accurate calculations

4

Get Results

View your ideal weight calculated by four formulas

Benefits of Knowing Your Ideal Body Weight

  • •
    Medical Reference: Used by healthcare providers for drug dosing and treatment planning.
  • •
    Fitness Planning: Helps set realistic weight goals for exercise programs.
  • •
    Nutrition Guidance: Provides a baseline for calculating caloric and nutritional needs.
  • •
    Health Monitoring: Serves as a reference point for tracking health changes over time.

Factors That Affect Ideal Body Weight

1. Body Frame Size

People with larger frames naturally have higher ideal weights than those with smaller frames.

2. Muscle Mass

Athletes and muscular individuals may weigh more than their IBW due to increased muscle mass.

3. Age

Ideal weight may change with age due to metabolic and body composition changes.

Formula Comparison: Which Gives Highest/Lowest Results

Different formulas can yield different results. Here's how they compare:

Height Highest Lowest Range
5'2" (157cm) Robinson: 118 lbs Devine: 111 lbs 7 lbs
5'6" (168cm) Robinson: 142 lbs Miller: 135 lbs 7 lbs
5'10" (178cm) Robinson: 166 lbs Miller: 158 lbs 8 lbs
6'2" (188cm) Robinson: 190 lbs Devine: 182 lbs 8 lbs

Note: Examples shown for males. Differences between formulas typically range 5-10 lbs.

Formula History: Why Each Was Created

Devine Formula (1974) - Most Popular

Purpose: Developed by Dr. B.J. Devine for calculating medication dosages, particularly for drugs where overdose risk is high.

Why It's Used: Simple, widely accepted in medical practice, and produces moderate results. Became the gold standard for clinical applications.

Robinson Formula (1983)

Purpose: Created to refine the Devine formula with updated population data from the early 1980s.

Why It's Used: Tends to give slightly higher values than Devine, better for larger-framed individuals. Popular in nutrition counseling.

Miller Formula (1983)

Purpose: Developed alongside Robinson with different coefficients, emphasizing a more conservative approach.

Why It's Used: Generally produces the lowest IBW values, suitable for smaller-framed individuals or those seeking conservative targets.

Hamwi Formula (1964) - Oldest

Purpose: One of the earliest formulas, created for quick clinical estimates using simple arithmetic.

Why It's Used: Very easy mental calculation, still used for rapid assessments. Results fall between Devine and Robinson.

Real-World Examples by Height

5'2" (157 cm) - Petite Frame

Female IBW: 106-118 lbs (48-54 kg)

Male IBW: 111-123 lbs (50-56 kg)

Common in East Asian and Hispanic populations. Higher muscle mass individuals may be at upper range or slightly above.

5'6" (168 cm) - Average Female Height

Female IBW: 120-135 lbs (54-61 kg)

Male IBW: 135-150 lbs (61-68 kg)

Most common height for women in many countries. Healthy range varies significantly based on activity level and body composition.

5'10" (178 cm) - Average Male Height

Female IBW: 148-166 lbs (67-75 kg)

Male IBW: 158-176 lbs (72-80 kg)

Average height for men in US/Europe. Athletes and active individuals often exceed upper range while remaining healthy.

6'2" (188 cm) - Tall Frame

Female IBW: 176-194 lbs (80-88 kg)

Male IBW: 182-200 lbs (83-91 kg)

Taller individuals with athletic builds often exceed these values. Consider body composition over absolute weight.

Which Formula is Right for You?

Choose based on your body type and goals:

Use Devine Formula If:

  • You have a medium/average frame
  • You want the most widely accepted medical standard
  • You need a middle-ground estimate
  • You're calculating medication dosages

Use Robinson Formula If:

  • You have a larger or broader frame
  • You're athletic with higher muscle mass
  • Previous formulas seem too low for your build
  • You're planning nutrition/fitness goals

Use Miller Formula If:

  • You have a smaller or petite frame
  • You prefer conservative weight estimates
  • Other formulas seem too high
  • You're setting initial weight loss goals

Use Hamwi Formula If:

  • You need quick mental calculations
  • You want results between Devine and Robinson
  • You're doing rapid clinical assessments

Frame Size Adjustments for Accuracy

Adjust your IBW based on bone structure and frame size:

Determining Your Frame Size

Wrist Method: Wrap thumb and middle finger around opposite wrist.

  • Small Frame: Fingers overlap significantly
  • Medium Frame: Fingers just touch
  • Large Frame: Fingers don't touch

Small Frame

Adjustment: Subtract 5-10% from calculated IBW. These individuals naturally carry less weight on a smaller skeletal structure.

Medium Frame

Adjustment: Use calculated IBW as-is. This represents the standard baseline for the formulas.

Large Frame

Adjustment: Add 5-10% to calculated IBW. Broader shoulders and bone structure support additional healthy weight.

Example: If Devine formula gives 150 lbs and you have a large frame, your adjusted IBW might be 158-165 lbs.

Related Health Calculators

Ideal Body Weight Calculator - Free online tool to calculate ideal body weight using Devine, Robinson, Miller, and Hamwi formulas based on height and gender
Professional ideal body weight calculator interface with metric and imperial unit options for height input. Provides instant calculations using four different formulas including Devine, Robinson, Miller, and Hamwi with healthy weight range recommendations and responsive design.

Frequently Asked Questions (FAQ)

Q: What is ideal body weight?

A: Ideal body weight (IBW) is a weight range that is considered healthy for a person based on their height and gender. It was originally developed for medical dosing purposes but is now used as a general health guideline. IBW represents a weight associated with maximum life expectancy and minimal health risks.

Q: How is ideal body weight calculated?

A: Ideal body weight is calculated using various formulas, with the most common being the Devine formula (1974). Other popular methods include the Robinson, Miller, and Hamwi formulas. These formulas use height and gender as primary inputs, with some variations accounting for frame size or body type.

Q: Is ideal body weight the same as healthy weight?

A: Not necessarily. Ideal body weight is a specific calculation, while healthy weight is a broader range. The healthy weight range is typically defined as a BMI between 18.5 and 24.9, which may be wider than the IBW range. IBW is just one tool among many for assessing healthy weight.

Q: Why do different formulas give different results?

A: Different formulas were developed for different purposes and populations. The Devine formula (1974) was created for drug dosing, while others like Robinson and Hamwi were developed later with different methodologies. Each formula may produce slightly different results, which is why our calculator provides results from multiple formulas for comparison.