Male
Female
Biological sex is used in standard medical formulas.
Feet
Inches
Please enter a valid height.
Medium Frame (Average)
Small Frame (-10%)
Large Frame (+10%)
Adjusts the target weight for bone structure.
Estimated Healthy Weight Range
144 – 176 lbs
Based on Healthy BMI (18.5 – 22.5)
Devine Formula
160 lbs
Robinson Formula
158 lbs
Miller Formula
155 lbs
Formula Explanation: The main range is derived from the World Health Organization's healthy BMI standards. The specific values use the Devine (1974), Robinson (1983), and Miller (1983) medical formulas adjusted for height and gender.
Weight Formulas Comparison
Method
Result (lbs)
Result (kg)
Everything You Need to Know to Calculate Weight You Should Be
Determining your ideal body weight is a fundamental step in managing your long-term health, fitness, and nutritional goals. When you calculate weight you should be, you are not just looking for a single magic number, but rather a healthy range that supports your vital organs, energy levels, and longevity. This guide explores the science behind weight calculations, explains the formulas used by medical professionals, and provides actionable insights for interpreting your results.
What is "Calculate Weight You Should Be"?
To calculate weight you should be implies finding the Ideal Body Weight (IBW). IBW is a clinical standard used by doctors and dietitians to estimate a healthy weight for a person based on their height, gender, and sometimes bone frame size. Unlike aesthetic goals, which are subjective, the calculation of ideal weight is rooted in mortality and morbidity statistics.
This tool is designed for adults (18+) who want to understand where they stand medically. It is not appropriate for children, pregnant women, or elite athletes with extremely high muscle mass, as standard formulas may misinterpret muscle weight as excess fat.
Common Misconception: Many believe there is only one "perfect" weight. In reality, a healthy weight is a range. Two people of the same height can vary by 15-20 pounds and both be metabolically healthy due to differences in muscle density and bone structure.
Formulas and Mathematical Explanation
When you calculate weight you should be, several established medical equations are used. The most common was developed to determine medication dosages but is now widely used for general health assessment.
The Devine Formula (1974)
This is the most widely used formula in medical settings.
Men: 50.0 kg + 2.3 kg per inch over 5 feet
Women: 45.5 kg + 2.3 kg per inch over 5 feet
The Robinson Formula (1983)
A modification of the Devine formula to be more accurate for modern populations.
Men: 52 kg + 1.9 kg per inch over 5 feet
Women: 49 kg + 1.7 kg per inch over 5 feet
Variable Reference Table
Variable
Meaning
Typical Range
Base Weight
Starting calculation point at 5ft height
45.5kg – 56.2kg
Height Factor
Weight added per inch of height > 60″
1.36kg – 2.7kg
Frame Adjustment
Correction for bone density
+/- 10%
Practical Examples (Real-World Use Cases)
Example 1: The Average Male
John is a 35-year-old male, 5 feet 10 inches tall (70 inches total). He wants to calculate weight he should be to reduce his risk of heart disease.
Height over 5ft: 10 inches
Calculation (Devine): 50kg + (2.3kg × 10) = 73kg
Conversion: 73kg ≈ 161 lbs
Interpretation: A target of around 161 lbs is medically ideal, though a range of 150-175 lbs is likely healthy based on BMI.
Example 2: The Petite Female
Sarah is 5 feet 2 inches tall (62 inches). She feels she should weigh 100 lbs but wants to verify this medically.
Interpretation: Her medically ideal weight is closer to 115 lbs. 100 lbs might be considered underweight for her height depending on her frame size.
How to Use This Calculator
Select Gender: Men and women carry muscle and fat differently, altering the baseline calculation.
Enter Height: Input your height in feet and inches accurately. Even one inch can change the result by 3-5 pounds.
Choose Frame Size: If you have a wrist circumference larger than average, choose "Large Frame" to adjust the result upward by 10%.
Review Results: Look at the "Estimated Healthy Weight Range". This is your primary goal zone.
Key Factors That Affect Your Result
When you calculate weight you should be, consider these six crucial factors that simple formulas might miss:
Muscle Mass: Muscle tissue is denser than fat. An athletic person might weigh significantly more than their "ideal" formula weight but have a low body fat percentage and be perfectly healthy.
Bone Density: Frame size accounts for bone thickness. Someone with a large frame naturally carries more non-fat mass.
Age: Metabolic rate slows with age, and muscle mass tends to decrease. "Ideal" weight often creeps up slightly in older age to provide a reserve against illness.
Hydration Levels: Daily weight can fluctuate by 1-4 lbs based on water retention, salt intake, and hydration status.
Fat Distribution: Visceral fat (around organs) is riskier than subcutaneous fat. Two people with the same weight might have different health risks depending on where the fat is stored.
Pregnancy & Breastfeeding: These biological states require additional weight for the health of the mother and child. Standard formulas do not apply here.
Frequently Asked Questions (FAQ)
Does this calculator apply to children?
No. Children and teenagers are still growing, and their weight-to-height ratio changes rapidly. Pediatricians use specific growth charts (percentiles) rather than static formulas to calculate weight they should be.
Why do different formulas give different results?
The formulas (Devine, Robinson, Miller) were developed based on different population data sets at different times. The Devine formula is the most common for medical dosing, while BMI ranges are used for general obesity screening.
Is it better to be at the lower end of the range?
Not necessarily. Being underweight carries its own risks, including weakened immunity and bone loss. Aiming for the middle of the healthy BMI range is often the safest strategy for long-term health.
How does frame size affect the calculation?
Frame size is typically determined by wrist circumference relative to height. A large frame allows for a heavy weight calculation (usually +10%) without classifying the individual as overweight.
Can I calculate weight I should be if I am very tall?
Yes, but linear formulas tend to become less accurate at extreme heights (under 5'0″ or over 6'6″). In these cases, BMI is often a better standardized metric.
Does muscle weigh more than fat?
A pound is a pound, but muscle is much more compact. One pound of muscle takes up less space than one pound of fat. Therefore, a muscular person will look leaner than a non-muscular person at the same weight.
How often should I check my ideal weight?
Your ideal weight based on height doesn't change once you stop growing. However, you should monitor your actual weight weekly to ensure you remain within your healthy range.
What if I am far from my result?
If you calculate weight you should be and find a large discrepancy, do not panic. Use this as a guide to set incremental goals. Losing even 5-10% of body weight can significantly improve health markers.
Related Tools and Resources
Explore our other health and fitness tools to support your journey:
BMI CalculatorCalculate your Body Mass Index for general health screening.
Body Fat CalculatorEstimate your body fat percentage based on tape measurements.