Ideal Body Weight Calculator

Calculate your ideal body weight using multiple scientific formulas (Devine, Miller, Robinson, Lemmens) and your Body Mass Index (BMI).

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in
lbs

Quick Facts

Healthy BMI Range
18.5 - 24.9
Normal weight category
Most Common Formula
Devine (1974)
Used in medicine
IBW Purpose
Drug Dosing
Originally developed for
Best Measure
Body Composition
IBW is just one factor

Your Ideal Weight Results

Calculated
Devine Formula
--
Most common
Miller Formula
--
Slightly higher
Robinson Formula
--
Moderate estimate
Lemmens Formula
--
BMI-based
Your BMI
--
Body Mass Index

Key Takeaways

  • Ideal Body Weight (IBW) formulas were originally designed for drug dosing calculations
  • The Devine formula is most commonly used in clinical settings
  • BMI between 18.5-24.9 is considered healthy for most adults
  • IBW formulas don't account for muscle mass, bone density, or body composition
  • Use multiple formulas together for a more complete picture

Understanding Ideal Body Weight

Ideal Body Weight (IBW) represents the optimal weight a person should maintain for good health based on their height and gender. While the term suggests a single perfect weight, it's better understood as a healthy weight range that varies by individual factors.

IBW calculations were originally developed in the 1970s for medical purposes, particularly for calculating drug dosages. Today, they serve as useful reference points for health assessments, though they should be considered alongside other measures like body composition and overall fitness.

The Four IBW Formulas Explained

Devine Formula (1974) - Most Common

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

Originally developed for drug dosing, this is the most widely used formula in clinical practice.

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

Tends to give slightly higher values than Devine, especially for taller individuals.

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

Provides moderate estimates between Devine and Miller formulas.

Lemmens Formula (2005)

IBW = 22 x height(m)^2

Based on achieving a BMI of 22 (middle of healthy range). Gender-neutral and modern approach.

Understanding Body Mass Index (BMI)

Body Mass Index (BMI) is calculated by dividing your weight in kilograms by your height in meters squared. It provides a quick assessment of whether you're in a healthy weight range.

BMI Range Category Health Risk
Below 18.5 Underweight Increased risk of nutritional deficiencies
18.5 - 24.9 Normal Weight Lowest health risk
25.0 - 29.9 Overweight Moderate risk increase
30.0 and above Obese Higher risk of chronic conditions

Limitations of IBW and BMI

  • Muscle mass: Athletes may be classified as overweight despite low body fat
  • Age: Body composition changes with age, but formulas don't adjust
  • Ethnicity: Different populations may have varying healthy weight ranges
  • Bone structure: Frame size isn't considered in these calculations
  • Body composition: Fat distribution matters more than total weight

How to Use This Calculator

  1. Enter your height in either imperial (feet/inches) or metric (meters/centimeters) units
  2. Enter your current weight for BMI calculation
  3. Select your gender (required for Devine, Miller, and Robinson formulas)
  4. Click "Calculate" to see results from all four formulas plus your BMI
  5. Use the average of multiple formulas as a general target range

When to Consult a Healthcare Provider

While IBW calculators provide useful estimates, you should consult a healthcare provider if:

  • Your BMI is significantly outside the normal range
  • You're planning major weight loss or gain
  • You have underlying health conditions
  • You're an athlete or have high muscle mass
  • You're pregnant or nursing