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Ideal Weight Calculator - Find Your Healthy Weight by Height

Free ideal weight calculator using Robinson, Miller, Devine, and Hamwi formulas. Calculate your ideal body weight based on height and gender with scientific accuracy.

9 min read

iAbout This Calculator

Determining your ideal body weight (IBW) is an important step in setting realistic health and fitness goals. Our free ideal weight calculator uses four scientifically established formulas - Robinson (1983), Miller (1983), Devine (1974), and Hamwi (1964) - to provide you with a comprehensive range of healthy weight targets based on your height and gender. Unlike single-formula calculators, our tool gives you multiple reference points, helping you understand that ideal weight exists within a range rather than as a single number. These formulas have been used by healthcare professionals for decades to estimate medication dosages, set weight management goals, and assess nutritional status.

?How to Use

  1. 1

    Enter your height in centimeters. If you know your height in feet and inches, multiply feet by 30.48 and inches by 2.54, then add them together.

  2. 2

    Select your gender. The formulas use different base weights and coefficients for males and females due to natural differences in body composition.

  3. 3

    Click Calculate to see your results. The calculator will display ideal weights from all four formulas plus an overall range and average.

  4. 4

    Review the formula comparison section to see how each method calculates your ideal weight, including the specific formula used.

  5. 5

    Use the average or range as a general target for your health goals, keeping in mind that individual factors may adjust your personal ideal weight.

fFormula

\text{IBW}_{\text{Robinson}} = 52 + 1.9 \times (\text{height in inches} - 60) \text{ for men}

The Robinson formula (most commonly used) calculates ideal body weight as: Men: 52 kg + 1.9 kg for each inch over 5 feet. Women: 49 kg + 1.7 kg for each inch over 5 feet. Miller, Devine, and Hamwi formulas follow similar patterns with different base weights and multipliers.

IBW
Ideal Body Weight in kilograms
height
Your height, converted to inches for the calculation
gender
Male or female, affecting base weight and multiplier values

Examples

Average Height Male (175 cm)

Inputs: height: 175, gender: male
66.1 - 72.7 kg

For a 175 cm (5'9") male: Robinson = 70.3 kg, Miller = 67.3 kg, Devine = 72.7 kg, Hamwi = 66.1 kg. Average: 69.1 kg.

Average Height Female (163 cm)

Inputs: height: 163, gender: female
52.0 - 57.2 kg

For a 163 cm (5'4") female: Robinson = 56.8 kg, Miller = 58.5 kg, Devine = 54.7 kg, Hamwi = 54.3 kg. Average: 56.1 kg.

Tall Male (188 cm)

Inputs: height: 188, gender: male
73.9 - 85.7 kg

For a 188 cm (6'2") male: Robinson = 80.0 kg, Miller = 74.6 kg, Devine = 84.7 kg, Hamwi = 79.6 kg. Taller individuals have wider ranges.

Petite Female (152 cm)

Inputs: height: 152, gender: female
45.5 - 53.1 kg

For a 152 cm (5'0") female at the base height: Robinson = 49.0 kg, Miller = 53.1 kg, Devine = 45.5 kg, Hamwi = 45.5 kg.

Use Cases

Weight Loss Goal Setting

Set realistic weight loss targets based on scientifically derived ideal weights. Having a range helps you choose a goal that accounts for your body type and lifestyle.

Medical Dosage Calculations

Healthcare providers often use ideal body weight to calculate medication dosages, particularly for drugs where actual body weight may lead to overdosing in obese patients.

Nutritional Assessment

Dietitians and nutritionists use IBW to assess nutritional status and create personalized meal plans that support achieving or maintaining a healthy weight.

Fitness Program Design

Personal trainers use ideal weight calculations to help clients set achievable targets and design workout programs aligned with body composition goals.

Pre-operative Assessment

Surgeons may use IBW to assess surgical risk and plan procedures, as being significantly over or under ideal weight can affect surgical outcomes.

Frequently Asked Questions

Which ideal weight formula is most accurate?
No single formula is universally most accurate. The Robinson formula is most commonly used in clinical settings, while Devine is often used for drug dosing. Using multiple formulas provides a realistic range. The Miller formula tends to give higher estimates, while Hamwi often gives lower values.
Why do different formulas give different results?
Each formula was developed using different study populations and methodologies at different times. The variations reflect the inherent difficulty in defining a single 'ideal' weight, which is why using a range from multiple formulas is more practical than relying on one.
Is ideal body weight the same as healthy weight?
Not exactly. Ideal body weight formulas estimate a target based on height and gender, while 'healthy weight' considers additional factors like age, body composition, fitness level, and overall health. A BMI of 18.5-24.9 is generally considered healthy, which may differ from IBW calculations.
Can I use this calculator if I'm very tall or very short?
The formulas are most accurate for heights between 152 cm (5'0") and 193 cm (6'4"). For extreme heights, the linear extrapolation may be less accurate. Consult with a healthcare provider for personalized assessment if you're outside this range.
How does muscle mass affect ideal weight?
These formulas don't account for muscle mass. Muscular individuals may weigh more than their calculated IBW while still being healthy. If you have significant muscle mass, consider body fat percentage as a better indicator of healthy weight.
Should I aim for the average or the range?
The range acknowledges that there's no single perfect weight. Generally, aim for the middle of the range if you have a medium frame, lower end for small frames, and higher end for large frames. The average provides a central reference point for goal setting.
Why are the formulas different for men and women?
Men and women have different body compositions on average. Men typically have more muscle mass and bone density, resulting in higher ideal weights at the same height. Women naturally carry more essential body fat, reflected in the lower base weights and coefficients.
Are these formulas suitable for older adults?
The formulas were developed using younger adult populations. Older adults may benefit from slightly higher body weights, as some research suggests a BMI of 23-27 may be optimal for those over 65. Consult with a healthcare provider for age-appropriate targets.

Conclusion

The ideal weight calculator provides valuable reference points for setting health and fitness goals based on established scientific formulas. By presenting results from four different methods, it acknowledges that ideal weight exists as a range rather than a fixed number. Use these calculations as starting points for discussions with healthcare providers, and remember that factors like muscle mass, frame size, age, and overall health status all influence what weight is truly ideal for you. Combined with BMI, body fat percentage, and regular health checkups, this tool can help guide your journey toward optimal health.

Last updated: January 6, 2026

Author: Calcoul Team

Reviewed by: Dr. Health Sciences

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