Free Ideal Weight Calculator Online
4-formula comparison: Devine, Miller, Robinson & Hamwi with BMI range
There is no single universally agreed definition of "ideal weight" — different clinical formulas developed over decades give different results depending on their intended use. This calculator computes your ideal weight using four established formulas (Devine, Miller, Robinson, and Hamwi) alongside the WHO BMI-based healthy range, letting you see where the consensus lies.
Frequently Asked Questions
About the Ideal Weight
The four ideal weight formulas in this calculator were each developed for different clinical purposes. The Devine formula (1974) was originally created to calculate drug dosing for patients — not as a fitness target. The Hamwi formula is used in clinical nutrition to determine caloric requirements. Robinson and Miller updated these models in 1983 using different population datasets.
Each formula was derived from height-based linear regressions of population samples, which is why they produce slightly different results. None of them account for muscle mass, frame size, or ethnicity — a heavily muscled athlete and a sedentary person of the same height would get the same "ideal weight" from every formula.
Think of these values as a range rather than a fixed target. If all four formulas and the BMI range overlap on a similar number, that convergence is meaningful. Where they diverge, your frame size, fitness goals, and personal health context matter more than any single formula's output.
When Should You Use This?
The Ideal Weight is ideally suited for fitness enthusiasts, healthcare professionals, and individuals monitoring their health who need to perform quick, accurate calculations related to general calculations. Use this tool when you need to verify figures, compare different scenarios, or get a precise answer without manual computation errors.
What Does The Result Mean?
The calculated metrics provide a scientifically validated baseline for your health or fitness goals. While these numbers are highly accurate based on standard medical formulas, they should serve as a guide rather than a replacement for professional medical advice.
Example Calculation
Ideal weight estimates for a 5'10" (178 cm) male
📥 Inputs
- Sex: Male
- Height: 178 cm (5 ft 10 in)
🔢 Calculation Steps
- 1Devine formula (1974): 50 + 2.3 × (inches over 5 ft) = 50 + 2.3 × 10 = 73.0 kg
- 2Miller formula (1983): 56.2 + 1.41 × (inches over 5 ft) = 56.2 + 14.1 = 70.3 kg
- 3Robinson formula (1983): 52 + 1.9 × (inches over 5 ft) = 52 + 19 = 71.0 kg
- 4Hamwi formula (1964): 48.0 + 2.7 × (inches over 5 ft) = 48 + 27 = 75.0 kg
- 5WHO BMI-based range (18.5–24.9): 58.7 kg – 79.1 kg
Limitations of this Calculator
- Formulas are based on population averages and may not perfectly reflect individuals with extreme muscle mass or atypical body compositions.
- Does not replace a physical examination or clinical diagnosis by a certified medical professional.
- Calculations cannot account for underlying metabolic conditions or genetic factors that influence individual health metrics.
How to Use the Ideal Weight
- 1Enter your values into the Ideal Weight input fields above.
- 2Review the input labels to ensure you are using the correct units.
- 3Click the "Calculate" button to get your instant result.
- 4Use the step-by-step breakdown to understand how the result was calculated.
- 5Export or copy your result to use in reports or share with others.
Tips & Best Practices
- No single formula is 'correct' — we show all four plus the BMI range so you can see the consensus.
- Double-check your input units before calculating — using the wrong unit is the most common source of errors.
- Bookmark this Ideal Weight for quick access next time you need it.
- Use the share button to send your results to a colleague or save them for later reference.
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⚠️ Health Disclaimer: Results provided by this calculator are for informational and educational purposes only. They do not constitute medical advice. Always consult a qualified healthcare professional, doctor, or registered dietitian before making any health, fitness, or dietary decisions.