Devine Weight Calculator
Estimate your ideal body weight using the Devine Formula.
Devine Weight Calculator
Male
Female
Select your biological sex.
Enter height in feet (e.g., 5).
Enter remaining height in inches (0-11).
Medium
Small
Large
Estimate your frame size: Small (bones feel light), Medium (average), Large (bones feel heavy).
Your Ideal Weight Range
— kg
— kg
Lower Bound
— kg
Upper Bound
— cm
Height in cm
The Devine formula estimates ideal body weight based on height, sex, and frame size, providing a healthy range.
What is the Devine Weight Calculator?
The Devine Weight Calculator is a tool designed to estimate an individual's ideal body weight. It uses the Devine formula, developed by Dr. W. M. Devine in 1974, which is a simple yet effective method for calculating a healthy weight range based on a person's height, sex, and an estimation of their skeletal frame size. This calculator serves as a helpful guide for individuals and healthcare professionals looking to establish a target weight that promotes good health and well-being.
The Devine formula provides a baseline ideal weight, and it's important to remember that it's a guideline, not a definitive medical prescription. Factors like muscle mass, body composition, and individual health conditions can influence what is a truly healthy weight for a specific person. Therefore, while the Devine Weight Calculator is an excellent starting point, it should always be used in conjunction with professional medical advice.
Who Should Use It?
- Individuals seeking to understand a healthy weight goal for their height.
- People interested in tracking their weight in relation to a calculated ideal.
- Healthcare providers looking for a quick reference point for ideal weight estimation.
- Anyone curious about the physiological basis of weight and height correlations.
Common Misconceptions
- It's the only way to determine a healthy weight: The Devine formula is a guideline, not a strict rule. Body composition (muscle vs. fat) is crucial and not accounted for directly.
- It accounts for muscle mass: The formula assumes an average body composition and may overestimate ideal weight for very muscular individuals.
- It's a diagnosis tool: It's a calculation tool for ideal weight estimation, not a diagnostic instrument for health conditions.
- Ideal weight is static: Life stages, activity levels, and health changes can alter what is an appropriate weight.
Devine Weight Calculator Formula and Mathematical Explanation
The Devine formula for calculating ideal body weight is a straightforward, linear equation that has been widely used for decades. It differs slightly based on sex and incorporates adjustments for frame size. The original formulas are:
For Men:
Ideal Body Weight (kg) = 50 kg + 2.3 kg for each inch over 5 feet
For Women:
Ideal Body Weight (kg) = 45.5 kg + 2.3 kg for each inch over 5 feet
Our calculator refines this by first converting total height into inches and then applying the formula. It also provides a range by adjusting for frame size, typically +/- 10% for small frames and +/- 10% for large frames relative to the medium frame calculation.
Step-by-step Derivation and Calculation:
- Convert Height to Total Inches: The total height in inches is calculated by multiplying the feet by 12 and adding the inches.
- Calculate Inches Over 5 Feet (60 inches): Subtract 60 inches from the total height in inches. If the height is 5 feet or less, this value is 0.
- Calculate Base Ideal Weight: Apply the sex-specific formula:
- Men: 50 + (Inches Over 5 Feet * 2.3)
- Women: 45.5 + (Inches Over 5 Feet * 2.3)
- Adjust for Frame Size:
- Small Frame: Subtract 10% from the base ideal weight.
- Medium Frame: Use the base ideal weight as calculated.
- Large Frame: Add 10% to the base ideal weight.
Variables Table:
| Variable | Meaning | Unit | Typical Range / Options |
|---|---|---|---|
| Height (ft & in) | Individual's stature. | Feet, Inches | Variable |
| Sex | Biological sex, affecting baseline weight. | Categorical | Male, Female |
| Frame Size | Skeletal structure size. | Categorical | Small, Medium, Large |
| Base Ideal Weight | Calculated weight before frame adjustment. | kg | Varies with height and sex |
| Weight Lower Bound | Ideal weight adjusted for a smaller frame. | kg | Varies |
| Weight Upper Bound | Ideal weight adjusted for a larger frame. | kg | Varies |
Practical Examples (Real-World Use Cases)
Example 1: A Man of Average Build
Inputs:
- Sex: Male
- Height: 5 feet 10 inches
- Frame Size: Medium
Calculation Breakdown:
- Total Height: (5 * 12) + 10 = 70 inches.
- Inches Over 5 feet: 70 – 60 = 10 inches.
- Base Ideal Weight (Male): 50 kg + (10 * 2.3 kg) = 50 + 23 = 73 kg.
- Frame Size Adjustment: Medium frame uses base weight.
Outputs:
- Ideal Weight: 73 kg
- Weight Range: 73 kg (Lower Bound, as Medium is the base) to 73 kg (Upper Bound, as Medium is the base)
- Height: 177.8 cm
Interpretation: For a 5'10" male with a medium frame, the Devine formula suggests an ideal weight of approximately 73 kg. This is a single point estimate for a medium frame.
Example 2: A Woman with a Larger Frame
Inputs:
- Sex: Female
- Height: 5 feet 4 inches
- Frame Size: Large
Calculation Breakdown:
- Total Height: (5 * 12) + 4 = 64 inches.
- Inches Over 5 feet: 64 – 60 = 4 inches.
- Base Ideal Weight (Female): 45.5 kg + (4 * 2.3 kg) = 45.5 + 9.2 = 54.7 kg.
- Frame Size Adjustment: Large frame adds 10%.
- Lower Bound: 54.7 kg * 0.90 = 49.23 kg (Small frame calculation for context).
- Upper Bound: 54.7 kg * 1.10 = 60.17 kg.
Outputs:
- Ideal Weight: 54.7 kg (This is the base medium-frame estimate)
- Weight Range: 49.2 kg to 60.2 kg
- Height: 162.56 cm
Interpretation: For a 5'4″ female with a large frame, the Devine formula indicates a healthy weight range between approximately 49.2 kg and 60.2 kg. The 54.7 kg is the estimate for a medium frame, with the range reflecting skeletal variations.
How to Use This Devine Weight Calculator
Using the Devine Weight Calculator is simple and designed for quick estimation. Follow these steps:
Step-by-Step Guide:
- Select Sex: Choose "Male" or "Female" from the dropdown menu.
- Enter Height: Input your height in feet and then in inches. Ensure accuracy for a precise calculation. For example, 5 feet 8 inches should be entered as 5 in the feet field and 8 in the inches field.
- Estimate Frame Size: Select "Small," "Medium," or "Large." If you're unsure, a medium frame is usually a good starting point. A small frame typically means your wrist measurement is smaller than average, while a large frame means it's larger than average.
- Click Calculate: Press the "Calculate Ideal Weight" button.
- Review Results: The calculator will display your estimated ideal weight, a healthy weight range adjusted for frame size, and your height in centimeters.
- Reset or Copy: Use the "Reset" button to clear the fields and start over, or "Copy Results" to save the displayed figures.
How to Read Results:
- Primary Result (Ideal Weight): This is the calculated weight for a medium frame, serving as the central point of your ideal weight.
- Weight Range (Lower/Upper Bound): This range accounts for variations in skeletal frame size. For instance, a large frame might suggest a weight towards the upper end of the range, while a small frame might suggest the lower end.
- Height in cm: A conversion of your entered height for additional reference.
- Formula Explanation: Briefly reiterates that the Devine formula is used, offering a guideline.
Decision-Making Guidance:
The Devine Weight Calculator provides an estimate. Use these results as a motivational tool or a starting point for discussions about health and fitness goals. If your current weight falls significantly outside the calculated range, it might be beneficial to consult with a healthcare professional to discuss healthy weight management strategies tailored to your individual needs and health status. Factors like muscle mass, fitness level, and underlying medical conditions are critical and not captured by this formula.
Key Factors That Affect Devine Weight Calculator Results
While the Devine formula is a useful tool, several factors can influence its applicability and the interpretation of its results. Understanding these can provide a more nuanced view of healthy weight management.
1. Body Composition (Muscle vs. Fat)
The Devine formula doesn't differentiate between lean muscle mass and body fat. Highly muscular individuals, such as athletes or bodybuilders, may weigh more than the calculated ideal weight due to muscle density, even if they have low body fat and are very healthy. The formula assumes an average body composition.
2. Frame Size Estimation
The frame size adjustment (small, medium, large) is an estimation. Methods like measuring wrist circumference or elbow breadth are imprecise. Misjudging frame size can lead to an ideal weight range that doesn't accurately reflect an individual's skeletal structure.
3. Sex and Hormonal Differences
While the formula has sex-specific starting points, biological sex influences body composition (e.g., typical fat distribution, bone density) in complex ways beyond just the initial constants. Hormonal fluctuations can also affect weight and body composition over time.
4. Age and Metabolism
Metabolism tends to slow with age, which can affect body weight and composition. The Devine formula doesn't account for age-related metabolic changes, meaning the ideal weight calculated might need adjustment for older adults.
5. Genetics
Genetics play a significant role in determining body type, metabolism, and where fat is stored. Some individuals are naturally predisposed to carrying more weight or having a larger frame, which the formula might not fully capture.
6. Lifestyle and Activity Level
A very active person with a rigorous exercise routine will likely have more muscle mass and a different body composition than a sedentary person of the same height and sex. The Devine formula provides a general estimate that doesn't consider the impact of exercise on weight and muscle development.
7. Underlying Health Conditions
Certain medical conditions (e.g., thyroid disorders, edema, hormonal imbalances) and medications can significantly impact body weight. The Devine formula cannot account for these health-related factors.
8. Fluid Retention and Hydration
Short-term fluctuations in body weight due to fluid retention (influenced by diet, medication, or hormonal cycles) are not considered by the formula and can temporarily skew weight readings relative to the ideal.
Frequently Asked Questions (FAQ)
What is the difference between Devine's formula and BMI?
BMI (Body Mass Index) is a ratio of weight to height squared (kg/m²). It's a population-level screening tool but doesn't account for body composition or frame size. The Devine formula specifically estimates an *ideal* weight based on height, sex, and frame size, providing a target range rather than a broad classification like underweight, normal, overweight, or obese.
Can the Devine formula be used for children?
No, the Devine formula was developed for and is intended for adult use. Calculating ideal weight for children requires different growth charts and pediatric-specific assessment tools.
How accurate is the Devine formula?
The Devine formula is considered a reasonable estimate for ideal body weight, especially for the general population. However, its accuracy can be limited for individuals with very muscular builds, certain medical conditions, or unusually large or small frames. It's best viewed as a starting point.
Should I aim for the exact middle of the Devine weight range?
The middle of the range is the base calculation for a medium frame. Whether you should aim for the middle, lower, or upper end depends on your individual body composition, muscle mass, fitness level, and personal health goals. Consulting a healthcare provider is recommended for personalized targets.
What if my height is exactly 5 feet?
If your height is exactly 5 feet (60 inches), the "inches over 5 feet" calculation will be 0. The formula will then simplify to the base weight constant: 50 kg for men and 45.5 kg for women. Frame size adjustments will then apply to these base weights.
Does frame size matter significantly?
Yes, frame size is a key factor in the Devine formula's adjustment. A larger frame typically means denser bones and a broader skeletal structure, justifying a higher ideal weight compared to someone of the same height and sex but with a smaller frame. The +/- 10% adjustment attempts to account for this.
Can I use this calculator if I'm pregnant?
No, the Devine Weight Calculator is not suitable for use during pregnancy. Pregnancy involves significant physiological changes and weight gain that are specific to the condition and require medical monitoring.
How often should I re-evaluate my ideal weight?
Your ideal weight may change over time due to aging, lifestyle changes, or health status. It's reasonable to re-evaluate your ideal weight using the calculator annually or whenever you experience significant changes in your activity level, diet, or health. However, prioritize your doctor's advice over calculator results.