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Ideal Weight Calculator ⚖️

Find your ideal body weight using 5 validated scientific formulas — Robinson, Miller, Devine, Hamwi & BMI range. Get your healthy weight range instantly.

Height Unit
Enter height between 100–250 cm
2–120 years
To see how far you are from ideal
Average Ideal Body Weight
Formula Breakdown
Average
kg
Recommended
Robinson
kg
1983
Miller
kg
1983
Devine
kg
1974
Hamwi
kg
1964
📏
Healthy BMI weight range (18.5 – 24.9)
⚠️ Medical Disclaimer: This tool provides estimates for informational purposes only. Ideal weight varies based on muscle mass, bone density, ethnicity, and individual health conditions. Always consult a qualified healthcare professional before making health decisions.

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How to Use the Ideal Weight Calculator

1
Select Your Gender
Choose Male or Female — IBW formulas use gender-specific constants for accuracy.
2
Enter Your Height
Switch between cm or feet/inches. Enter your standing height without shoes.
3
Enter Your Age
Age helps contextualize your results. IBW formulas are validated for adults aged 18+.
4
Add Current Weight (Optional)
Enter your current weight to see exactly how much you are above or below ideal.
5
Click Calculate
See your ideal weight from 5 formulas, average recommendation, BMI healthy range, and your current weight status.

About Ideal Body Weight Formulas

Ideal Body Weight (IBW) formulas were originally developed in clinical medicine to calculate drug dosages. Over time, they became widely used as a reference for healthy weight goals. Each formula uses height and gender as inputs, with slightly different constants.

The 5 Formulas We Use

FormulaYearMale (base)Female (base)Per inch above 5ft
Robinson198352 kg49 kg+1.9 / +1.7 kg
Miller198356.2 kg53.1 kg+1.41 / +1.36 kg
Devine197450 kg45.5 kg+2.3 / +2.3 kg
Hamwi196448 kg45.4 kg+2.7 / +2.27 kg
BMI RangeWHO18.5–24.9 × height² (m²)

Which Formula Should I Trust?

No single formula is universally superior. The Robinson formula is considered the most accurate for general population use. The Devine formula is most widely used in clinical practice for medication dosing. The WHO BMI range is the gold standard for population-level health assessment. Our calculator shows the average of all four IBW formulas as the primary recommendation.

Limitations of IBW Formulas

IBW formulas do not account for muscle mass, bone density, ethnicity, or body composition. An athlete may weigh significantly more than their calculated IBW and still be in excellent health. Always use IBW as a general reference — not a strict target — and consult a healthcare provider for personalised guidance.

BMI Healthy Weight Range

A BMI between 18.5 and 24.9 is classified as "Normal weight" by the World Health Organization. The healthy BMI weight range for your height gives you a broader target zone that aligns with long-term health outcomes in large population studies.

Frequently Asked Questions

Ideal body weight (IBW) is a target weight range associated with optimal health for a given height and gender. It is calculated using validated medical formulas like Robinson, Devine, Miller, and Hamwi.
No single formula is universally best. The Devine formula is most used clinically for drug dosing. Robinson (1983) is considered most accurate for the general population. We recommend using the average of all formulas shown.
Not exactly. Ideal weight is formula-derived from height and gender. Healthy weight is typically defined as a BMI between 18.5 and 24.9. The BMI-based healthy weight range is often broader than IBW formula results.
Yes. Men generally have higher bone density and muscle mass, so IBW formulas apply different base values and per-inch increments for men and women at the same height.
IBW formulas are based on average body composition. Athletes with high muscle mass may weigh more than IBW suggests while still being very healthy. Use IBW as a general reference, not an absolute target.
Yes, 100% free. No signup or registration required. All calculations run instantly in your browser — no data is sent or stored.