Ideal Weight Calculator - Find Your Ideal Body Weight Free Ideal Weight Calculator
Calculate your ideal body weight using four scientific formulas — Devine, Robinson, Miller and Hamwi. Enter your gender and height to see recommended ideal weight range.
Your Details
Your Results
Ideal Weight by Formula Male
| Formula | Ideal Weight (kg) | Ideal Weight (lbs) |
|---|---|---|
| Devine | 68.0 | 149.9 |
| Robinson | 66.5 | 146.6 |
| Miller | 66.1 | 145.7 |
| Hamwi | 68.2 | 150.4 |
Ideal Weight Calculator - Guide
What is Ideal Body Weight (IBW)?
Ideal Body Weight (IBW) is an estimated weight range based on your height and gender that is associated with the lowest health risk and optimal well-being. Developed by medical researchers over several decades, ideal weight formulas provide a science-based reference point for healthy weight targets.
While no single number defines the “perfect” weight, comparing results from multiple formulas gives a reliable recommended range. This free online ideal weight calculator uses four well-established medical formulas — Devine, Robinson, Miller, and Hamwi — to calculate your ideal body weight for your height and gender, along with the healthy BMI-based weight range for additional context.
Key Features of This Ideal Weight Calculator
- Four Scientific Formulas: Calculates ideal weight using Devine, Robinson, Miller, and Hamwi formulas simultaneously.
- Gender-Specific Results: Select Male or Female for gender-appropriate ideal weight estimates.
- Dual Height Input: Enter height in centimetres or switch to feet/inches using the toggle.
- Recommended Range: Displays the range across all four formulas as your practical ideal weight target.
- BMI-Based Range: Shows the healthy weight range corresponding to a BMI of 18.5–24.9 for additional reference.
- Formula Comparison Table: View ideal weight from each formula in both kilograms and pounds.
Ideal Weight Formulas — How Ideal Body Weight Is Calculated
Devine Formula (1974):
Men: IBW = 50 + 2.3 × (height in inches − 60)
Women: IBW = 45.5 + 2.3 × (height in inches − 60)
Robinson Formula (1983):
Men: IBW = 52 + 1.9 × (height in inches − 60)
Women: IBW = 49 + 1.7 × (height in inches − 60)
Miller Formula (1983):
Men: IBW = 56.2 + 1.41 × (height in inches − 60)
Women: IBW = 53.1 + 1.36 × (height in inches − 60)
Hamwi Formula (1964):
Men: IBW = 48.0 + 2.7 × (height in inches − 60)
Women: IBW = 45.5 + 2.2 × (height in inches − 60)
All formulas return results in kilograms. Height baseline is 5 feet (60 inches / 152.4 cm).
How to Use This Ideal Weight Calculator — Step-by-Step
- Select Your Gender: Click Male or Female. Each formula uses different constants for men and women.
- Enter Your Height: Type your height in centimetres, or toggle to feet/inches and enter both values.
- Click "Calculate Ideal Weight": View your recommended weight range, healthy BMI range, and formula comparison table.
- Review the Table: Compare ideal weight estimates from all four formulas in both kg and lbs.
Practical Examples of Ideal Weight Calculation
Example 1 — Male, 170 cm (5’7” / 67 inches):
- Devine: 50 + 2.3 × (67 − 60) = 50 + 16.1 = 66.1 kg
- Robinson: 52 + 1.9 × 7 = 65.3 kg
- Miller: 56.2 + 1.41 × 7 = 66.1 kg
- Hamwi: 48.0 + 2.7 × 7 = 66.9 kg
- Recommended Range: 65.3–66.9 kg
Example 2 — Female, 162 cm (5’4” / 64 inches):
- Devine: 45.5 + 2.3 × (64 − 60) = 45.5 + 9.2 = 54.7 kg
- Robinson: 49 + 1.7 × 4 = 55.8 kg
- Miller: 53.1 + 1.36 × 4 = 58.5 kg
- Hamwi: 45.5 + 2.2 × 4 = 54.3 kg
- Recommended Range: 54.3–58.5 kg
When to Use an Ideal Weight Calculator — Real-World Scenarios
- Setting Weight Goals: Establish a realistic target weight based on your height and gender before starting a diet or fitness programme.
- Medical Assessments: Healthcare providers use IBW for drug dosing, ventilator settings, and nutritional assessments.
- Fitness Planning: Use ideal weight as a benchmark alongside body fat percentage and BMI for comprehensive fitness tracking.
- Insurance & Screening: Some health insurance and wellness programmes reference ideal weight ranges.
- Pre-Surgery Evaluation: Surgeons may reference IBW when planning procedures or assessing anaesthesia requirements.
Understanding Your Ideal Weight Results
- Recommended Range: The span between the lowest and highest ideal weight across all four formulas. This is your practical target range.
- Healthy BMI Range: The weight range that corresponds to a BMI of 18.5–24.9 for your height. This provides broader context — your actual ideal weight may fall anywhere within this range depending on body composition.
- Formula Variations: Each formula was developed from different study populations and time periods. The variation between them reflects the inherent uncertainty in defining a single “ideal” weight.
- Individual Factors: Your actual ideal weight depends on muscle mass, bone density, body frame, age, and overall health — factors these formulas do not measure.
Tips for Reaching and Maintaining a Healthy Weight
- Balanced Diet: Focus on whole foods — vegetables, fruits, lean proteins, whole grains, and healthy fats.
- Regular Exercise: Combine cardiovascular exercise (150+ min/week) with strength training (2–3 sessions/week) for optimal body composition.
- Gradual Changes: Aim for 0.25–0.5 kg per week weight change for sustainable, long-lasting results.
- Stay Hydrated: Drink adequate water throughout the day — roughly 35 ml per kg of body weight.
- Monitor Multiple Metrics: Track weight, body measurements, body fat percentage, and how clothes fit rather than relying on the scale alone.
- Be Patient: Healthy weight management is a marathon, not a sprint. Focus on sustainable habits over quick fixes.
Limitations & Medical Disclaimer
- No Body Composition: These formulas do not account for muscle mass, body fat percentage, or bone structure. Athletes may weigh more than IBW and still be very healthy.
- Height Constraint: All formulas use 5 feet (60 inches / 152.4 cm) as the baseline. Results for individuals shorter than this are extrapolated and less reliable.
- Not Universal: Formulas were developed using specific populations (primarily Western) and may not apply equally across all ethnicities and body types.
- Age Not Considered: Body composition changes with age, but these formulas do not adjust for it.
- Not Medical Advice: These are statistical estimates, not clinical targets. Your doctor may recommend a different weight range based on your specific health profile.
Disclaimer: This ideal weight calculator is provided for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Consult a qualified healthcare provider for personalised weight and health guidance.
Frequently Asked Questions About Ideal Weight
Q: Which ideal weight formula is the most accurate?
A: The Devine formula is the most widely used in clinical settings (e.g., drug dosing and ventilator settings). However, since all formulas are estimates, comparing results from all four gives the most reliable range.
Q: Does ideal weight account for body composition?
A: No. Ideal weight formulas are based only on height and gender. They do not account for muscle mass, bone density, or body fat percentage. Athletes and muscular individuals may weigh more than the ideal range and still be perfectly healthy.
Q: How is ideal weight different from BMI?
A: Ideal weight formulas give a specific weight target in kilograms based on height and gender. BMI is a ratio of weight to height that categorises you into health risk groups. Both are screening tools, not definitive health measures.
Q: Can my ideal weight change over time?
A: The formula-based IBW does not change (it depends only on height and gender). However, your personal optimal weight may shift with age, muscle gain, health conditions, and lifestyle changes. Regular check-ups with your doctor can help you adjust your targets.