Ideal Body Weight
Your Ideal Body Weight varies based on gender, age, and current health. This ideal weight calculator is an approximation and based on the Broca’s Index.
Broca’s Index for IBW: Height (in Cm) – 100
Broca Index Calculator – Calculate Your Ideal Body Weight
The Broca Index is one of the simplest methods to estimate your ideal body weight based on your height. Originally developed by French surgeon Paul Broca, this formula provides a quick way to determine whether your body weight falls below, within, or above the recommended range.
Our Broca Index Calculator helps you instantly calculate your ideal weight in kilograms. In addition to the Broca formula, the calculator also compares your results using the BMI method and the Devine Formula, giving you a more comprehensive understanding of your healthy weight range.
Whether you’re planning a weight-loss journey, muscle-building program, or simply tracking your fitness goals, knowing your ideal body weight can help you make better health decisions.
What Is the Broca Index?
The Broca Index is an ideal weight estimation method that calculates healthy body weight based primarily on height. Unlike BMI, which considers both height and weight to classify health status, the Broca Index focuses on estimating what your body weight should ideally be.
The formula is easy to understand and has been used for decades as a quick screening tool. Although modern healthcare professionals often rely on BMI and body fat percentage for a more accurate assessment, the Broca Index remains popular because of its simplicity.
What Is the Broca Index Formula and How Does It Work?
The original Broca’s Index Formula is:
Ideal Body Weight (kg) = Height (cm) − 100
For example:
- Height: 170 cm
- Ideal Weight = 170 − 100 = 70 kg
Modified versions of the formula are sometimes used:
For Men
Ideal Weight = (Height in cm − 100) × 0.9
For Women
Ideal Weight = (Height in cm − 100) × 0.85
These adjusted formulas account for average differences in body composition between men and women.
Step-by-Step Guide to Calculating Your Broca Index
- Enter your height.
- Select your gender.
- Click Calculate.
- View your ideal weight based on the Broca formula.
- Compare the result with BMI and Devine Formula estimates.
The calculator provides an estimated healthy weight range rather than an exact target, helping you better understand your current body weight.
Using the Broca Formula to Estimate Your Ideal Weight
The calculation follows three easy steps:
- Measure your height in centimeters.
- Apply the Broca formula.
- Compare your current weight with the calculated ideal weight.
Example:
Height = 175 cm
Ideal Weight = 175 − 100 = 75 kg
If your actual weight is close to this value, you may be within the recommended weight range according to the Broca method.
Broca Index Body Weight Classification
After calculating your ideal weight, compare it with your current weight.
If Below Ideal Weight
Being significantly below your ideal weight may indicate inadequate calorie intake, nutritional deficiencies, or underlying medical conditions. Increasing protein intake, resistance training, and consulting a healthcare professional can help achieve healthy weight gain.
If At Ideal Weight
Maintaining your ideal weight supports better energy levels, mobility, and overall health. Continue following a balanced diet, regular physical activity, and healthy lifestyle habits.
If Above Ideal Weight
If your weight exceeds the Broca Index recommendation, gradual weight management through calorie control, regular exercise, and improved nutrition can help reduce health risks associated with excess body weight.
Broca Index for Obesity
The Broca Index can provide a basic indication of excess body weight, but it should not be used alone to diagnose obesity.
Healthcare professionals generally prefer BMI, waist circumference, body fat percentage, and metabolic health assessments when evaluating obesity.
The Broca Index is best used as an initial reference rather than a clinical diagnostic tool.
Broca Index Compared with BMI, Devine Formula & Other Methods
| Method | Uses | Best For |
| Broca Index | Height | Quick estimation |
| BMI | Height & Weight | Population screening |
| Devine Formula | Height & Gender | Medical calculations |
| Body Fat Percentage | Fat Mass | Fitness assessment |
| Waist-to-Height Ratio | Fat Distribution | Metabolic risk |
Why One Formula Isn't Enough to Estimate Ideal Weight
No single formula accurately predicts ideal body weight for everyone.
Factors like:
- Muscle mass
- Bone density
- Age
- Gender
- Body frame
- Ethnicity
all influence healthy weight.
Using multiple methods provides a more balanced assessment than relying solely on one calculation.
Three Popular Ways to Estimate Your Healthy Weight
Method 1 – BMI Method for Estimating Healthy Weight
BMI estimates healthy weight based on height and categorizes individuals as underweight, healthy weight, overweight, or obese.
Method 2 – Broca Index Method
The Broca method estimates ideal body weight using height and optional gender adjustments.
Method 3 – Devine Formula for Ideal Body Weight
The Devine Formula is widely used in healthcare for estimating ideal body weight, particularly when calculating medication dosages.
How to Read Your Ideal Weight Calculator Results
After using the calculator, your result represents an estimated ideal body weight.
It is not a diagnosis.
Your result should be interpreted alongside:
- BMI
- Waist circumference
- Body fat percentage
- Overall health
- Fitness goals
Ideal Weight for Women - Height and Weight Chart (Female)
| Height | Ideal Weight |
| 150 cm | 43–48 kg |
| 155 cm | 47–52 kg |
| 160 cm | 50–56 kg |
| 165 cm | 54–60 kg |
| 170 cm | 58–65 kg |
| 175 cm | 63–70 kg |
Ideal Weight for Men - Height and Weight Chart (Male)
| Height | Ideal Weight |
| 160 cm | 52–58 kg |
| 165 cm | 56–62 kg |
| 170 cm | 60–67 kg |
| 175 cm | 65–72 kg |
| 180 cm | 70–78 kg |
| 185 cm | 75–84 kg |
Average Healthy Weight by Age - Weight Chart for Adults
Age alone does not determine ideal body weight, but metabolism, muscle mass, hormonal changes, and activity levels often change over time.
Adults should focus on maintaining a healthy weight range while preserving lean muscle through proper nutrition and regular exercise.
BMI Range Chart - What Your BMI Category Means
| BMI | Category |
| Below 18.5 | Underweight |
| 18.5–24.9 | Healthy Weight |
| 25–29.9 | Overweight |
| 30+ | Obesity |
What Determines Your Healthy Body Weight?
Your ideal body weight depends on more than height.
Important factors include:
- Age
- Gender
- Muscle mass
- Bone structure
- Genetics
- Physical activity
- Overall health
- Nutrition
This is why weight calculators should be used as guidance rather than strict targets.
Training Recommendations Based on Broca Index
If Below Ideal Weight
Focus on:
- Strength training
- Progressive overload
- High-protein nutrition
- Healthy calorie surplus
If At Ideal Weight
Maintain:
- Regular resistance training
- Cardio
- Balanced nutrition
- Adequate sleep
If Above Ideal Weight
Prioritize:
- Moderate calorie deficit
- Resistance training
- Daily walking
- Cardio sessions
- High-protein meals
Benefits of Knowing Your Ideal Weight
Understanding your ideal weight can help you:
- Set realistic fitness goals
- Track weight-loss progress
- Improve overall health awareness
- Reduce obesity-related health risks
- Plan balanced nutrition
- Support long-term wellness
Who Created the Broca Index? A Brief History
The Broca Index was introduced in the 19th century by Paul Broca, a French surgeon and anthropologist. It was originally designed as a simple method to estimate an adult’s ideal body weight using height. Before modern body composition tools were available, the Broca formula gained popularity because it required only one measurement and could be calculated quickly.
While today’s healthcare professionals often use BMI, body fat percentage, and other clinical assessments for greater accuracy, the Broca Index remains a useful educational tool and a convenient starting point for understanding healthy weight.