Ideal Body Weight Calculator

Ideal Body Weight (IBW) is a value used primarily in medical settings, such as drug dosing and nutritional planning, to estimate the weight at which an individual has the lowest risk of death based on their height and sex.

The World Health Organization (WHO) considers a healthy body mass index (BMI) to fall between 18.5 and 25 for both men and women, serving as a useful measure of whether a person’s weight is appropriate for their height. Understanding where you fall within this range can help identify potential health risks related to being underweight, overweight, or obese, and guide decisions toward maintaining a balanced, healthy lifestyle.

To take it a step further, you can determine your ideal body weight using our online IBW calculator.

This tool uses the Devine formula, factoring in your height, age, and gender, to provide a personalized estimate of what your ideal weight should be, but it doesn't fully capture individual body composition or unique biological differences.

Ideal Body Weight (IBW)

Ideal Body Weight (IBW) is an estimate of a healthy weight for an individual, primarily based on height, sex, and sometimes body frame. It is commonly used in medicine for drug dosing, such as antibiotics or during mechanical ventilation, and for assessing nutritional needs.

IBW is often calculated using the Devine formula (e.g., males: 50 kg + 2.3 kg per inch over 5 ft; females: 45.5 kg + 2.3 kg per inch over 5 ft) or derived from Body Mass Index (BMI).

Ideal Body Weight (IBW) is the optimal weight for health, calculated primarily based on a person’s height and sometimes adjusted for sex and body frame size. It is often used as a reference in medical dosing, nutritional assessments, and body composition analysis.

IBW also plays a role in calculating Body Mass Index (BMI), which offers a broader estimate of overall health. It is not a fixed number, but rather varies with age, sex, and height.

Common Ideal Body Weight Calculator Formula

1. Ideal Body Weight Calculator Divine Formula

The Divine Formula is a well-known equation for estimating ideal body weight using just a height measurement. We will use inches for height in the following examples.

1. Women: ideal body weight = 45.5 kg + 2.3 kg x (height – 60)
2. Men: ideal body weight= 50 kg + 2.3 kg x (height – 60)

For example, a woman who is 65 inches tall, would have an ideal body weight of 57 kg.

Similarly, a man who is 75 inches tall, would have an ideal body weight of 84.5 kg.

2.Ideal body weight calculator Broca Formula

The Broca Index, also known as the Broca formula, was created in 1871 by the French physician, surgeon, and anthropologist Paul Broca. It's used to determine a person's normal weight. The formula is pretty straightforward. It just uses the height as its input. The only difference is for women where the ideal body weight is 10% less as shown in the examples below.

1. Men: ideal body weight: Height – 100
2. Women: ideal body weight: (Height – 100) * 0.9

For example: a man who is 175 cm tall would have an ideal body weight calculator in kg of 75

Similarly, a woman who is 165 cm tall would have an ideal body weight of (165 – 100) * 0.9 = 58.5 kg.

3.Ideal body weight calculator Lorentz Formula

1. For men: ideal body weight: (height cm – 100) – ((height – 150)/4)
2. For women: (height cm – 100) – ((height – 150)/2)

For example: a man who is 179 cm tall would have an ideal body weight of 72 kg.

Similarly, a woman who is 165 cm tall would have an ideal body weight calculator in kg of 57.5 kg.

4.Ideal body weight calculator Miller Formula

To get an accurate calculation, this formula requires you to measure your height in feet.

1. For men: ideal Body Weight = 56.2 kg + 1.41 kg per inch over 5 feet.
2. For women: Ideal Body Weight = 53.1 kg + 1.36 kg per inch over 5 feet.

For example, the weight of a man who is 5 feet 2 inches tall is calculated as the following:

5 feet allows for (56.2 kg) + 2 inches allows for (2* 1.41 kg) = 2.82. The total is 56.2+2.82 = 59 kg.

Similarly, a woman who is 5 feet 5 inches tall has an ideal body weight of:

5 feet allows for (53.1 kg) + 5 inches allows for (5*1.36 kg) = 6.8. The total is 53.1+ 6.8 = 60 kg.

5.Ideal body weight calculator hamwi formula

To get an accurate calculation, this formula requires you to measure your weight in pound or and your height in feet

1. Ideal body weight formula for men: 106 lbs (48 kg) for the first 5 feet (60 inches or 152.4 cm). Add 6 lbs (2.7 kg) for each inch (2.54 cm) over 5 feet.
2. Ideal body weight formula women: 100 lbs (45.5 kg) for the first 5 feet (60 inches or 152.4 cm). Add 5 lbs (2.3 kg) for each inch (2.54 cm) over 5 feet.

6.Ideal body weight calculator NHI formula

1. Males IBW Calculation: 50kg + 0.91kg * (height in cm –152.4)
2. Females IBW Calculation: 45.5kg + 0.91kg * (height in cm –152.4) * Revert to 5 feet when assigning Tidal Volume for all patients < 5 feet tall

7.Percentage of ideal body weight calculator

Used for both men and women shows This shows how much your current weight differs from your ideal weight, whether it’s higher or lower.

1. %IBW = (Actual Weight / Ideal Body Weight) * 100

Uses of IBW Calculator in Medicine

1. Medication Dosing: Helps determine appropriate drug dosages, particularly for obese patients, by calculating Adjusted Body Weight (ABW) using the formula:
2. ABW = IBW + 0.4 × (Actual Weight − IBW).
3. Mechanical Ventilation: Guides the setting of tidal volumes (breath size) to protect the lungs and prevent ventilator-induced lung injury (VILI).
4. Nutritional Assessment: Provides a baseline for evaluating nutritional status, complementing BMI measurements for a more accurate assessment.

Factors That Affect Ideal Body Weight Calculator

1. Height & Gender: Taller individuals generally weigh more, and men typically have more muscle and lower fat than women at the same height.
2. Body Frame Size: Wrist measurements indicate small, medium, or large-boned frames, affecting your ideal weight range.
3. Age: Metabolism slows with age, impacting fat and muscle gain or loss.
4. Muscle Mass: Muscle weighs more than fat, so very fit individuals may appear “overweight” on a basic BMI scale.
5. Body Fat Percentage: Fat distribution (waist vs. hips) and overall body composition matter more than weight alone.
6. Lifestyle & Genetics: Activity level, diet, sleep, stress, and family history all play a role in body composition.
7. Medical Conditions & Medications: Health issues and certain drugs can affect appetite, metabolism, and weight.

What is the Ideal Body Weight for an Individual?

In general, IBW is not a definitive factor for determining an individual's health status. BMI (body mass index) is a more precise indicator that is utilized in a medical context for the diagnosis of health-related conditions. However, some general charts provide a range of weight in relation to height for both sexes.

Ideal Body Weight Calculator Female:

Sex based women IBW formulas include Divine, Broca, Lorentz, and Miller formulas with adjustments specific for females. For women with an average height of 160 cm, the IBW is 47.2 – 57.6 kg

Ideal Male Body Weight Calculator:

The same Sex based formulas, Divine, Broca, Lorentz, and Miller , are used with constants adjusted for males, providing an accurate calculation based on height.For men with an average height of 160 cm, the IBW is 50.8 – 60.1 kg

Ideal body weight calculator by age

For adults, ideal body weight and body mass index formulas are based on height and gender, but not age. However, in pediatrics, ideal weight calculations consider age, with specific formulas for different stages.

Pediatric ideal body weight calculator

Ideal body weight calculator for infant < 12 months: Weight (kg) = (age in months + 9/2)

Ideal body weight calculator for pediatric and children: aged 1-5 years: Weight (kg) = 2 x (age in years + 5)

Ideal body weight calculator for children aged 5-14 years: Weight (kg) = 4 x age in years.

IBW for adult patients with anorexia nervosa

The ideal body weight calculator for anorexia is defined as having a body weight less than 85% of the ideal body weight, or a BMI of 17.5 or lower.

Importance of Ideal Body Weight

1. Health Risk Indicator. Maintaining an optimal body weight can help reduce the risk of developing chronic diseases such as cardiovascular disease, type 2 diabetes, and certain types of cancer.
2. Weight Management Goals. The primary objectives of weight loss management are to reduce body weight, maintain it over time, and prevent further weight gain. Your IBW can serve as a valuable reference point for monitoring your weight.
3. Personalized Nutritional Planning. Knowing your ideal body weight is a crucial initial step in making informed dietary decisions. It enables you to concentrate on specific food types that support optimal body function and maintain overall health.

Limitations of Ideal Body Weight Formulas

Ideal Body Weight (IBW) formulas have limitations because they are oversimplified. They often underestimate weight for shorter individuals and overestimate it for taller ones, failing to account for body composition (muscle vs. fat), age, ethnicity, and individual health conditions.

This can lead to inaccurate medication dosing and less reliable nutritional guidance, which is why many experts recommend using BMI or clinical judgment as more effective tools.

1. Ignores Body Composition: IBW does not distinguish between fat and muscle. A muscular individual may appear overweight despite having low body fat.
2. Doesn’t Account for Frame Size: Standard formulas do not fully consider body width, trunk length, or bone structure, which can influence a healthy weight.
3. Oversimplifies Health: IBW focuses on a single number, overlooking important factors like fat distribution (e.g., visceral fat) and overall health indicators.
4. Age & Gender Inaccuracies: The formulas may not accurately reflect age-related changes in body fat or variations in body types between genders.
5. Inaccurate for Extremes: IBW can be unreliable for very short or very tall individuals, or those with physical disabilities.
6. Medication Dosing Risks: Relying solely on IBW for drug dosing may result in under- or overdosing, especially in pediatric or critically ill patients.

Body Weight Formulas Other Than IBW

1. Body Mass Index (BMI)

The BMI is a simple medical screening tool that measures the ratio of your height to your weight to estimate the amount of body fat you have. Your healthcare provider can calculate your BMI by using your weight in kilograms (kg) divided by the square of your height in meters (m²).

1. Body Fat Percentage calculator

Your body fat percentage is a way of measuring how much of your body is made up of fat, bone, and muscle. A healthy body fat range is 25-31% for women and 18-24% for men.

1. Waist-to-Hip Ratio (WHR)

Calculating your WHR is one way your doctor can determine if being overweight is putting your health at risk. It determines how much fat is stored around your waist, hips, and buttocks. The WHR measures the ratio of your waist circumference to your hip circumference.

1. Body frame size and ideal weight calculator

Body frame size is usually determined by measuring your wrist circumference relative to your height.

People with larger frames often have higher bone density and may naturally weigh more than those with smaller frames, even if they have the same height and body fat percentage.

A waist circumference of 35 inches or greater for women, and 40 inches for men, indicates an elevated risk of obesity-related health complications.

To find your body frame size and ideal weight, first measure your wrist circumference relative to your height to determine if you're small, medium, or large-framed, then use this info with height in an online calculator or formula (like Devine's: 50kg + 2.3kg per inch over 5ft for men, 45.5kg + 2.3kg for women), adjusting your target BMI (lower for small frames, higher for large) for a more personalized healthy weight range

1. Adjusted ideal body weight calculator:

It is commonly used in medication dosing, as it depends on lean body mass without considering the amount of fat in your weight. AdjBW formula = IBW + 0.4 * (ABW - IBW)

1. Ideal weight and body fat calculator:

The body fat calculator measures the percentage of fat in your total body weight. It is an important indicator of excess fat, which can increase the risk of various diseases. Healthy body fat percentage ranges are 25–31% for women and 8–24% for men.

Calculate Your Ideal Body Weight by Tables

Ideal Body Weight (Devine) – Females

IBWfemale=45.5+2.3×(height in inches−60)IBW_{\text{female}} = 45.5 + 2.3 \times (\text{height in inches} - 60)IBWfemale​=45.5+2.3×(height in inches−60)

Ideal Body Weight (Devine) – Males

IBWmale=50+2.3×(height in inches−60)IBW_{\text{male}} = 50 + 2.3 \times (\text{height in inches} - 60)IBWmale​=50+2.3×(height in inches−60)

Interested in checking up your overall health? read about Health Check-Up Packages in Turkey: