Scientifically determine your ideal weight range and plan your journey
Male
Female
Biological sex affects body composition formulas.
Years (Adults 18+)
Please enter a valid age.
Feet and Inches
Please enter a valid height.
Your weight today in pounds.
Please enter a positive weight.
Sedentary (Office job)
Lightly Active (1-3 days/week)
Moderately Active (3-5 days/week)
Very Active (6-7 days/week)
Super Active (Physical job)
Used to calculate daily calorie burn.
Maintain Current Weight
Lose 0.5 lbs per week (Slow)
Lose 1.0 lbs per week (Recommended)
Lose 2.0 lbs per week (Aggressive)
Gain 0.5 lbs per week
Gain 1.0 lbs per week
Choose your desired pace.
Scientifically Ideal Body Weight (Average)
160 lbs
Based on composite of Devine, Robinson & Miller formulas
Healthy BMI Range
125 – 169 lbs
Daily Calories to Reach Goal
2,050 kcal
Weeks to Reach Ideal
20 Weeks
Weight Formula Comparison
Formula Method
Calculated Ideal Weight
Description
Projected Weight Trajectory
Projected progress over the next 12 weeks based on your selected strategy.
What is a Desired Body Weight Calculator?
A desired body weight calculator is a specialized tool designed to help individuals determine a healthy target weight based on physiological factors such as height, gender, and frame size. Unlike generic scales, this calculator uses medically validated formulas—such as the Devine, Robinson, and Miller equations—to provide a scientifically grounded estimation of what your "ideal" body weight (IBW) should be.
This tool is essential for anyone looking to set realistic fitness goals. Whether you are aiming for weight loss, muscle gain, or maintenance, knowing your calculated ideal weight provides a concrete baseline. It helps prevent setting arbitrary or unhealthy goals by anchoring your expectations in anthropometric data.
Common misconceptions often lead people to chase a "magic number" they saw on social media. However, true health is individual. This calculator accounts for your specific parameters to suggest a weight range that supports longevity and reduces the risk of chronic diseases associated with both underweight and obesity.
Desired Body Weight Formula and Mathematical Explanation
There is no single "perfect" formula, but several equations are widely accepted in the medical community for estimating Ideal Body Weight (IBW). Our calculator utilizes a composite average of these to provide the most balanced result.
1. The Devine Formula (1974)
Originally developed to calculate drug dosages, this is the most widely used formula.
Men: 50 kg + 2.3 kg per inch over 5 feet
Women: 45.5 kg + 2.3 kg per inch over 5 feet
2. Body Mass Index (BMI) Method
While not a direct formula for "ideal" weight, the World Health Organization defines a "healthy" BMI range as 18.5 to 24.9. We calculate the weight range that keeps you within these boundaries.
Formula: Weight = BMI × (Height in meters)²
Variables Table
Variable
Meaning
Unit
Typical Range
Height
Vertical stature
cm / ft-in
120 – 220 cm
Base Weight
Starting constant for gender
kg / lbs
45 – 50 kg
Increment
Weight added per unit of height
kg/inch
2.3 kg
TDEE
Total Daily Energy Expenditure
kcal
1200 – 3500+
Practical Examples (Real-World Use Cases)
Example 1: The Moderate Weight Loss Goal
Scenario: John is a 35-year-old male, 5'10" (178 cm), currently weighing 200 lbs. He works a desk job (Sedentary).
Ideal Weight (Devine): Approx 166 lbs.
Goal: Reach 166 lbs.
Strategy: 1 lb per week deficit.
Result: It will take approximately 34 weeks. His maintenance calories (TDEE) are ~2,200. To lose 1 lb/week, he needs to eat ~1,700 kcal/day.
Example 2: The Fitness Maintenance
Scenario: Sarah is a 28-year-old female, 5'5″ (165 cm), weighing 135 lbs. She is moderately active.
Ideal Weight (Robinson): Approx 130 lbs.
Analysis: She is already very close to her ideal weight and within the healthy BMI range (111 – 150 lbs).
Recommendation: Maintenance or very slow body recomposition. No aggressive dieting is required.
How to Use This Desired Body Weight Calculator
Enter Biological Details: Input your gender, age, and height accurately. These are the core variables for the IBW formulas.
Input Current Status: Enter your current weight and typical activity level. Be honest about activity—most people overestimate this!
Select Strategy: Choose how fast you want to move toward your goal (e.g., "Lose 1.0 lbs per week").
Analyze Results: Look at the "Scientifically Ideal Body Weight" as a reference point, not a strict rule. Check the "Weeks to Reach Ideal" to understand the time commitment.
Review the Chart: The "Projected Weight Trajectory" visualizes your journey, helping you mentally prepare for the duration of the process.
Key Factors That Affect Desired Body Weight Results
While formulas provide a target, real-world "ideal" weight depends on several complex factors:
Muscle Mass vs. Fat Mass: Muscle is denser than fat. An athlete may weigh more than the formula suggests but still be lean and healthy. The calculator cannot "see" your body composition.
Frame Size: People with larger bone structures (wrist circumference > 7 inches) may naturally carry more weight healthily than the formulas predict.
Age and Metabolism: As we age, metabolic rate often slows (approx 2% per decade). Maintaining a strictly "ideal" weight from your 20s might be harder in your 50s.
Water Retention: Daily weight can fluctuate by 2-5 lbs due to sodium intake and hydration, affecting your tracking vs. the calculator's linear projection.
Caloric Deficit Sustainability: A calculated "2 lbs/week" loss requires a 1000 calorie daily deficit, which may be chemically stressful and unsustainable long-term, leading to yo-yo dieting.
Hormonal Health: Factors like cortisol and insulin sensitivity affect how the body stores energy, potentially altering the "calories in, calories out" efficiency assumed by simple math.
Frequently Asked Questions (FAQ)
Is the calculated ideal weight mandatory for health?
No. It is a statistical average. Being 10-15 lbs above or below this number is often perfectly healthy, provided your body fat percentage and metabolic markers are good.
Which formula is the most accurate?
The Devine Formula is the standard for medical dosing, while the Robinson Formula was derived to improve it. For most people, the results are very similar. Our calculator shows an average to give you a balanced view.
Can I target a weight outside the healthy BMI range?
You can, but it is not recommended without medical supervision. The "Healthy BMI Range" we display represents the statistical "sweet spot" for lowest mortality risk.
Why does the calculator adjust calories for age?
The Mifflin-St Jeor equation used here accounts for the natural decline in Basal Metabolic Rate (BMR) as you age, ensuring your calorie target is realistic for your life stage.
What if I am an athlete?
Formulas based on height and weight (like BMI) fail for athletes with high muscle mass. Use this calculator as a rough guide, but rely more on body fat percentage measurements.
How often should I recalculate?
Every 4-6 weeks. As you lose weight, your metabolic needs decrease. You will need to adjust your calorie intake to continue making progress.
Does this calculator account for frame size?
Standard formulas like Devine do not. However, the BMI range (18.5-24.9) offers a wide buffer that generally accommodates small, medium, and large frames.
Is it safe to lose 2 lbs per week?
Generally, yes, for those with significant weight to lose. For those closer to their goal, 0.5 to 1 lb per week is better to preserve muscle mass.