Determine your ideal weight range using scientifically validated medical formulas.
Compare results from the Devine, Robinson, Miller, and Hamwi equations instantly.
Formulas differ significantly based on biological sex constants.
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Suggested Body Weight (Devine Formula)
166 lbs
136 – 184 lbs
Healthy BMI Range (18.5-24.9)
163 lbs
Robinson Formula
161 lbs
Miller Formula
Formula Used: The Devine Formula (1974) is the most widely used equation for medical dosing. For men, it calculates 50kg + 2.3kg per inch over 5 feet.
Formula Comparison
Formula Name
Calculated Weight
Primary Use Case
Comparison of the four major medical weight formulas.
Weight Analysis Chart
Visual comparison of calculated suggestions vs. BMI thresholds.
What is Suggested Body Weight?
The concept of suggested body weight (often referred to medically as Ideal Body Weight or IBW) is a calculation used to estimate a healthy weight target based on an individual's height and biological sex. While no single number defines health, these calculations provide a baseline for medical dosages, nutritional needs, and general health assessments.
It is important to understand that a suggested body weight calculator provides an estimate based on population averages. It does not account for muscle mass, bone density, or body composition. Therefore, athletes with high muscle mass may weigh more than the "suggested" value while maintaining a low body fat percentage and excellent health.
This tool is primarily useful for:
Setting realistic weight loss or gain goals.
Medical professionals calculating drug dosages.
Nutritional planning and caloric estimation.
Suggested Body Weight Formula and Mathematical Explanation
There are four primary formulas used to calculate suggested body weight. The most common is the Devine Formula, developed in 1974 to estimate the clearance of drugs in obese patients.
The Devine Formula (Standard)
Men: 50 kg + 2.3 kg × (Height in inches – 60) Women: 45.5 kg + 2.3 kg × (Height in inches – 60)
Variable Definitions
Variable
Meaning
Unit
Typical Range
Base Weight
Starting constant based on sex
kg
50 (M) / 45.5 (F)
Height Factor
Weight added per unit of height
kg/inch
2.3
Height Threshold
Height above which weight is added
inches
60 (5 feet)
Variables used in the standard Devine calculation.
Practical Examples (Real-World Use Cases)
Example 1: Male, 5ft 10in
Consider a male who is 5 feet 10 inches tall (70 inches total).
Base: 50 kg
Height over 5ft: 70 – 60 = 10 inches
Calculation: 50 + (2.3 × 10) = 50 + 23 = 73 kg
Result: ~161 lbs
Interpretation: This 161 lbs target serves as the center point for health metrics, though a healthy BMI range would extend roughly 15-20 lbs in either direction.
Example 2: Female, 5ft 4in
Consider a female who is 5 feet 4 inches tall (64 inches total).
Select System: Choose between Imperial (lbs/ft) or Metric (kg/cm) based on your preference.
Input Biological Sex: Select Male or Female. This adjusts the base constants in the math.
Enter Height: Input your height accurately. Small differences in height significantly affect the result.
Review Results: The calculator immediately updates. Look at the "Primary Result" for the Devine method value, but check the "Healthy BMI Range" for a broader, more flexible target.
Key Factors That Affect Suggested Body Weight Results
While the math is precise, the application to real human bodies is complex. Six key factors influence how you should interpret these results:
Muscle Mass: Muscle tissue is denser than fat. A bodybuilder may be "overweight" by these formulas but metabolically healthy.
Bone Density (Frame Size): Individuals with larger skeletal frames naturally weigh more. The Robinson formula is sometimes preferred for smaller frames.
Age: As we age, muscle mass tends to decrease and fat mass increases. Older adults may benefit from being slightly above the traditional IBW to provide a reserve against illness.
Pregnancy: These formulas are not valid for pregnant women, who have distinct weight gain requirements for fetal health.
Hydration Levels: Daily weight fluctuations of 1-3 lbs due to water retention are normal and do not reflect structural body weight changes.
Fat Distribution: Visceral fat (around organs) is a higher health risk than subcutaneous fat. Two people at the same "suggested weight" may have different health profiles based on where they carry weight.
Frequently Asked Questions (FAQ)
Why does the calculator give different results for different formulas?
Different researchers (Devine, Robinson, Miller) developed equations using different population data sets. Devine is the standard, but Miller often provides better estimates for very tall or short individuals.
Is suggested body weight the same as BMI?
No. BMI (Body Mass Index) is a ratio of weight to height that produces a score (e.g., 22.5). Suggested body weight gives you a specific target in pounds or kilograms.
Which result should I aim for?
Aim for the "Healthy BMI Range" rather than a single specific number. This allows for natural body variations and muscle mass.
Does this apply to children?
No. Children and adolescents require specialized growth charts (CDC or WHO percentiles) as their bodies are developing rapidly.
How often should I check my weight?
Weekly weigh-ins are generally sufficient to track trends without becoming obsessive over daily fluctuations.
Does frame size matter?
Yes. These formulas assume a "medium" frame. If you have a large frame (broad shoulders/wrists), increase the suggested weight by roughly 10%.
Is being under the suggested weight healthy?
Not necessarily. Being significantly underweight can lead to compromised immune function, osteoporosis, and hormonal imbalances.
Can I use this for athletic training?
Athletes should consult sports nutritionists. These general formulas usually underestimate the healthy weight of high-performance athletes due to muscle density.
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