Determine your Ideal Body Weight (IBW) and healthy weight range using medical formulas.
Male
Female
Gender affects the base calculation in most IBW formulas.
Enter height in centimeters (e.g., 175).
Please enter a valid height between 100cm and 250cm.
Used for detailed range estimation (optional).
Estimated Ideal Weight (Devine Formula)
70.0 kg
Based on the Devine (1974) formula, widely used for medical dosage.
Healthy BMI Range (18.5-24.9)56.7 – 76.2 kg
Robinson Formula (1983)71.1 kg
Miller Formula (1983)69.5 kg
Detailed Weight Analysis
Method
Result (kg)
Description
Table 1: Comparison of different ideal body weight calculation methods.
Healthy Weight Range Visualizer
Figure 1: Visual comparison of calculated Ideal Body Weight against the general healthy BMI range.
What is "Calculate Weight for Height in KG"?
To calculate weight for height in kg is to determine the optimal or "Ideal Body Weight" (IBW) for a specific individual based on their height and gender. Unlike simple weighing scales which only tell you your current mass, an IBW calculation provides a benchmark for health.
This calculation is widely used by medical professionals to determine dosages for medications, by dietitians to set weight loss goals, and by fitness enthusiasts to track progress. It is important to note that "ideal" weight is a statistical estimation derived from population averages and does not account for muscle mass, bone density, or body composition.
Common misconceptions include the belief that there is a single "perfect" weight. In reality, a healthy weight exists within a range (typically defined by BMI), and the specific "ideal" point varies depending on the mathematical formula applied.
Weight for Height Formulas and Mathematical Explanation
There are several scientifically validated formulas to calculate weight for height in kg. Most of these were originally developed for pharmaceutical use to estimate lean body mass.
1. The Devine Formula (1974)
This is the most widely used formula. It was originally intended to calculate gentamicin dosages.
Men: 50.0 kg + 2.3 kg per inch over 5 feet
Women: 45.5 kg + 2.3 kg per inch over 5 feet
2. The Robinson Formula (1983)
Developed as a refinement to the Devine formula.
Men: 52.0 kg + 1.9 kg per inch over 5 feet
Women: 49.0 kg + 1.7 kg per inch over 5 feet
3. The BMI Method
The Body Mass Index (BMI) offers a range rather than a specific number. To calculate weight for height in kg using BMI, we reverse the standard formula:
Weight = BMI × (Height in meters)²
Variables Table
Variable
Meaning
Unit
Typical Range
Height
Vertical stature
Centimeters (cm)
140cm – 210cm
Base Weight
Starting constant
Kilograms (kg)
45kg – 56kg
Increment
Added weight per inch
kg/inch
1.4kg – 2.7kg
Table 2: Key variables used in IBW formulas.
Practical Examples (Real-World Use Cases)
Example 1: Male, 180cm Tall
Let's calculate weight for height in kg for a 180cm (approx 5ft 11in) male.
Height: 180 cm (~71 inches)
Inches over 5ft (60in): 11 inches
Devine Calculation: 50 + (2.3 × 11) = 50 + 25.3 = 75.3 kg
Financial/Health Interpretation: This 75.3 kg is the target "reference" weight. If this individual weighs 95 kg, they are significantly above the statistical ideal, potentially indicating higher health insurance premiums or increased long-term medical costs associated with obesity.
Example 2: Female, 165cm Tall
Now, let's look at a female who is 165cm (approx 5ft 5in).
Outcome: A weight of 57.5 kg would be considered her specific ideal. However, the healthy BMI range for this height is roughly 50 kg to 68 kg, showing that the "ideal" is just one point within a healthy spectrum.
How to Use This Weight Calculator
Select Gender: Choose Male or Female. This adjusts the base constant in the formula (men generally have higher bone mass and muscle density averages).
Input Height: Enter your height in centimeters. Accuracy is key; even 2cm can change the result by nearly 1kg.
Review the Primary Result: The large highlighted number is your Devine Ideal Weight, the industry standard.
Check the Range: Look at the "Healthy BMI Range". As long as your actual weight falls within these bounds, you are statistically in a healthy category.
Analyze the Chart: Use the visual bar chart to see where the different formulas place your ideal weight compared to the healthy limits.
Key Factors That Affect Weight Results
When you calculate weight for height in kg, the result is a baseline. Several real-world factors influence what your actual healthy weight should be:
Muscle Mass: Muscle is denser than fat. An athlete may weigh significantly more than their "ideal" weight but have a low body fat percentage and excellent health.
Frame Size: Wrist circumference and elbow breadth indicate frame size. People with large frames naturally carry more weight (bone and connective tissue) than the formulas predict.
Age: Metabolism slows with age, and muscle mass often decreases while bone density changes. Older adults may be healthier at slightly higher weights to provide reserves against illness.
Bone Density: Genetic variances in bone mineral density can account for several kilograms of difference between two people of the exact same size.
Pregnancy and Nursing: Standard formulas do not apply to pregnant or nursing women, who have specific nutritional and weight requirements.
Health Conditions: Conditions like edema (water retention) can artificially inflate weight, making the "ideal" target seem further away than it is in terms of tissue mass.
Frequently Asked Questions (FAQ)
1. Which formula is the most accurate?
The Devine formula is the most widely accepted for medical use. However, the "BMI Range" is generally the most useful for the average person to assess general health.
2. Why is my ideal weight so low?
These formulas were created in the 1970s and 80s based on actuarial data derived from life insurance statistics. They tend to favor a very lean build which was statistically associated with longevity at that time.
3. Can I use this if I am under 5 feet tall?
Most IBW formulas start at 5 feet (60 inches). For heights under 5 feet, the calculator subtracts weight based on the formula, but results become less reliable mathematically.
4. Does this apply to children?
No. Children and teenagers are still growing, and their weight-for-height ratios vary wildly. Use a pediatric growth chart for individuals under 18.
5. Is a higher weight always unhealthy?
Not at all. If the excess weight is muscle (e.g., bodybuilders), a high BMI or weight-over-ideal is not a health risk. Waist circumference is often a better predictor of health risk than weight alone.
6. How do I convert feet to cm?
Multiply your height in feet by 30.48. For example, 6 feet is 6 × 30.48 = 182.88 cm.
7. What if I am "Skinny Fat"?
You might be at your "ideal weight" according to the calculator but have high visceral fat and low muscle. Body composition matters more than the scale number.
8. How often should I check this?
Adult height rarely changes, so your "Ideal Weight" target remains constant. However, you should monitor your actual weight weekly to ensure you stay within the Healthy BMI Range calculated here.