Ideal Weight Calculator — Free Ideal Body Weight Tool
Calculate your ideal body weight from height, age, and gender using proven medical formulas. Find a healthy target range in seconds, free.
Calculate your ideal body weight using multiple formulas
About this calculator
Comprehensive Guide to Ideal Body Weight
Ideal body weight is a target weight range that accounts for your height, gender, and frame size. Unlike BMI, which uses only height and weight, ideal body weight formulas were developed by medical professionals to provide a more personalized goal. These clinically validated equations are used by doctors, nutritionists, and fitness professionals to establish realistic weight targets for health, athletic performance, and aesthetic goals.
There are several established formulas for calculating ideal body weight, each developed through different methodologies. The Robinson, Miller, Devine, and Hamwi formulas are the most widely recognized. While they produce slightly different results, they all provide valid target ranges. Most people fall within 10-15 pounds of their calculated ideal weight range.
How to Use the Ideal Weight Calculator
Our ideal weight calculator helps you determine a healthy target weight:
Select Your Gender
- Male or Female
- Different formulas apply to each gender
Enter Your Height
- In feet and inches, or centimeters
- Used as the base for all ideal weight calculations
Select Your Frame Size (Optional)
- Small, medium, or large frame
- Allows ±10% adjustment to account for bone structure variation
View Your Ideal Weight Range
- Results from multiple formulas (Robinson, Miller, Devine, Hamwi)
- Average recommendation
- Frame-adjusted ranges for personalization
The Ideal Weight Formulas
Four major formulas are used to calculate ideal body weight, each developed through different clinical research.
The Robinson Formula (1983)
For Men:
Ideal Weight = 52 kg + 1.9 kg per inch over 5 feet
For Women:
Ideal Weight = 49 kg + 1.7 kg per inch over 5 feet
Example: A 5'10" (70 inches) male
- Base: 52 kg
- Additional: (70 - 60) × 1.9 = 19 kg
- Ideal Weight = 71 kg (156 lbs)
The Miller Formula (1983)
For Men:
Ideal Weight = 56.2 kg + 1.41 kg per inch over 5 feet
For Women:
Ideal Weight = 53.1 kg + 1.36 kg per inch over 5 feet
Example: A 5'6" (66 inches) female
- Base: 53.1 kg
- Additional: (66 - 60) × 1.36 = 8.16 kg
- Ideal Weight = 61.3 kg (135 lbs)
The Devine Formula (1974)
For Men:
Ideal Weight = 50 kg + 2.3 kg per inch over 5 feet
For Women:
Ideal Weight = 45.5 kg + 2.3 kg per inch over 5 feet
Example: A 5'8" (68 inches) male
- Base: 50 kg
- Additional: (68 - 60) × 2.3 = 18.4 kg
- Ideal Weight = 68.4 kg (150.6 lbs)
The Hamwi Formula (1964)
For Men:
Ideal Weight = 48 kg + 2.7 kg per inch over 5 feet
For Women:
Ideal Weight = 45.5 kg + 2.2 kg per inch over 5 feet
Example: A 5'4" (64 inches) female
- Base: 45.5 kg
- Additional: (64 - 60) × 2.2 = 8.8 kg
- Ideal Weight = 54.3 kg (119.5 lbs)
Frame Size Adjustments
Individual bone structure varies. Frame size allows ±10% adjustment:
| Frame Size | Adjustment | Example (Calculated: 150 lbs) |
|---|---|---|
| Small | -10% | 135 lbs |
| Medium | 0% | 150 lbs |
| Large | +10% | 165 lbs |
How to Estimate Frame Size:
- Wrap your thumb and middle finger around your wrist
- Small frame: Fingers overlap
- Medium frame: Fingers just touch
- Large frame: Fingers don't touch
Comparing the Four Formulas
| Formula | Method | Best For |
|---|---|---|
| Robinson | Lower baseline, moderate increments | General population, more conservative |
| Miller | Mid-range baseline and increments | Balanced approach |
| Devine | Lower baseline, higher increments | Taller individuals |
| Hamwi | Older formula, moderate increments | Medical/clinical use |
Example for 5'10" Male:
- Robinson: 156 lbs
- Miller: 161 lbs
- Devine: 179 lbs
- Hamwi: 184 lbs
- Average: 170 lbs
Most people fall within 5-10 lbs of the average of these formulas.
How Ideal Weight Differs From BMI
| Metric | What It Measures | Accounts For |
|---|---|---|
| Ideal Weight | Target weight range personalized to height and gender | Proportional body structure |
| BMI | General weight category based on height/weight | Population-level health risk screening |
| Body Fat % | Actual percentage of body weight that is fat | Distinguishes muscle from fat |
Key Difference: Two people at the same ideal weight can have very different body compositions. One might be muscular (athletic) while the other carries more fat. This is why body fat percentage is a complementary metric.
Practical Applications and Scenarios
Scenario 1: Setting a Weight Loss Goal
Profile: 5'8" female, currently 180 lbs, sedentary
Ideal weight calculation (average of four formulas):
- Estimated ideal weight range: 125-135 lbs
Action plan:
- Target: 130 lbs (middle of range)
- Current deficit needed: 50 lbs
- Timeline: 25-35 weeks at 1-1.5 lbs/week (healthy rate)
- Strategy: 500-750 calorie daily deficit
Scenario 2: Athlete Checking Body Composition Goal
Profile: 5'10" male, currently 175 lbs, trains 5x/week
Ideal weight calculation (average):
- Estimated ideal weight range: 155-170 lbs
Assessment:
- Current weight is above mid-range but within acceptable range
- If 20% body fat: ~140 lbs lean mass + 35 lbs fat
- Athlete strength and muscle mass are within range
- Could reduce to 165 lbs with better body composition (15% fat)
Scenario 3: Maintenance Mode
Profile: 5'6" female, currently 125 lbs, exercises 3x/week
Ideal weight calculation (average):
- Estimated ideal weight range: 120-130 lbs
Assessment:
- Current weight is at upper end of ideal range
- Good health markers, normal energy levels
- Focus on maintaining through consistent exercise and nutrition
- Monitor body composition rather than scale weight
Important Considerations
Ideal Weight Limitations
- Doesn't account for muscle mass: Athletes and muscular individuals may weigh more than "ideal" but be very healthy
- Doesn't measure body composition: You can be at ideal weight with poor body composition (high fat percentage)
- Varies by frame size: Exact ideal weight is a range, not a single number
- Individual variation: Genetics, hormones, and metabolism mean some people naturally weigh more or less
When Ideal Weight May Not Apply
- Competitive athletes: May have "ideal weights" 10-20 lbs above calculated due to muscle
- Older adults: May need slightly higher weights to maintain bone density and muscle mass
- Certain medical conditions: Thyroid disorders, medications, and health conditions affect ideal weight
- Pregnant women: Calculators designed for non-pregnant individuals
Tips for Using Ideal Weight as a Goal
- Set a weight range, not a single number — Aim for ±5 lbs of your calculated ideal
- Combine with body composition — Use body fat % or how clothes fit as additional metrics
- Prioritize consistency over speed — Slow, steady weight loss is more sustainable
- Monitor non-scale victories — Energy, strength, mood, and fitness matter more than exact weight
- Adjust based on your response — If you feel good, have energy, and look fit, you're at a healthy weight even if above "ideal"
- Work with professionals — For significant weight changes, consult your doctor or registered dietitian
Step-by-Step Example
Example Ideal Weight (5'10" Male)
- Height: 5'10" (70 inches)
- Devine: 50 + (2.3 × 10) = 73 kg (161 lbs)
- Miller: 56.2 + (1.41 × 10) = 70.2 kg (155 lbs)
- Robinson: 52 + (1.9 × 10) = 71 kg (156 lbs)
Frequently Asked Questions
Should I use one formula or average them?
Averaging the four formulas provides a balanced range. If most formulas cluster around a number, that's likely more accurate for you. Some people naturally fall outside the range—focus on how you feel and your body composition.
Is my ideal weight the same as my goal weight?
Not necessarily. Your ideal weight is a clinical target, but your personal goal might be higher (muscle gain) or lower (competitive leanness). Both can be healthy depending on your lifestyle and goals.
What if I'm significantly above my ideal weight?
This is common and very manageable. Focus on losing 1-2 lbs per week through sustainable habits. Reaching ideal weight in 1-2 years is much better than unsustainable crash dieting.
Does age affect ideal weight?
The standard formulas don't adjust for age, but as you age, slightly higher weights may be protective for bone density. Consult a healthcare provider for age-specific guidance if over 65.
How often should I recalculate?
Your ideal weight won't change unless your height or gender changes. You might recalculate if you have significantly changed frame size assessment (unlikely after age 25).
How realistic is achieving ideal weight? Ideal weight formulas are estimates. Genetics, body composition, and individual factors mean your healthy weight may differ from calculated results. Consult your doctor.
How realistic is achieving ideal weight?
Ideal weight formulas are estimates. Genetics, body composition, and individual factors mean your healthy weight may differ from calculated results. Consult your doctor.
Related Calculators
BMI Calculator • TDEE Calculator • Calorie Calculator • Body Fat Calculator
Sources & References
- CDC - Healthy Weight
- WHO - Weight Classification
- NIH - Weight Research
- Academy of Nutrition and Dietetics - Weight Management
Disclaimer
This calculator is provided for educational and informational purposes only. It is not medical, fitness, nutritional, or professional advice. Results are estimates based on the assumptions and inputs you provide.
Actual results may differ significantly due to:
- Individual variations in metabolism and physiology
- Changes in activity level, diet, and lifestyle
- Age, genetics, and medical conditions not accounted for
- Equipment calibration and measurement accuracy
- Environmental and seasonal factors
Do not rely on this calculator for:
- Medical diagnosis or treatment decisions
- Personalized fitness or nutrition planning without professional input
- Determining safe exercise intensity or duration
- Managing health conditions
- Making major life or health decisions
Before making any health or fitness decisions, consult with:
- A licensed physician or healthcare provider
- A registered dietitian or nutrition specialist
- A certified fitness trainer or exercise physiologist
- A medical professional if you have health conditions
Past performance and estimates do not guarantee future results. Always verify important information independently and consult qualified professionals for your individual circumstances.
Frequently Asked Questions
What formulas does the Ideal Weight Calculator use?
The calculator typically applies several well-known medical formulas, including Devine, Robinson, Miller, and Hamwi — each developed for clinical use and each yielding slightly different results. Showing multiple estimates gives you a range rather than a single fixed number, which better reflects real-world variation.
How is ideal body weight different from BMI-based healthy weight?
BMI-based healthy weight uses only height and weight with no frame-size consideration. Ideal body weight formulas were originally developed for medication dosing in clinical settings and factor in height and sex; some versions also adjust for body frame size (small, medium, large). The two approaches often produce overlapping but not identical ranges.
What inputs do I need to use this calculator?
You need your height and sex assigned at birth at minimum. If the calculator includes frame-size adjustment, you may also measure your wrist circumference or elbow breadth to determine whether you have a small, medium, or large frame.
Should I aim to reach my calculated ideal weight?
Not necessarily. Ideal body weight formulas were designed for drug-dosing estimation, not as fitness goals. A more meaningful target is a weight at which you feel healthy, maintain good energy, and have favorable clinical markers (blood pressure, cholesterol, blood sugar). A registered dietitian or doctor can help set a realistic, personalized target.
Are these formulas accurate for athletes or very tall or short individuals?
The classic formulas were derived from average-build populations and can be less accurate at height extremes or for athletes with high muscle mass. For muscular individuals, the calculated ideal weight may seem low; for very short or very tall people, the linear extrapolation may not hold well. Use the result as a rough guide, not a strict target.
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