Ideal Weight Calculator
Calculate your ideal weight range by height and gender.
How to use Ideal Weight Calculator
Select Your Gender
Click the gender dropdown menu at the top of the calculator and choose either 'Male' or 'Female'. This selection adjusts the calculation formula based on average body composition differences between genders.
Enter Your Height
Input your height in the 'Height' field. Select your preferred unit (feet/inches or centimeters) from the dropdown next to the input box. For example, enter '5' in feet and '10' in inches, or '178' in centimeters.
View Your Ideal Weight Range
Click the blue 'Calculate' button below the input fields. Your personalized ideal weight range will instantly display in pounds or kilograms, showing both minimum and maximum recommended weight based on your height and gender.
Related Tools
Ideal weight calculator: find your healthy weight range
Ideal weight calculator: find your healthy weight range
Wondering what your ideal body weight should be based on your height? Use ToolHQ's Ideal Weight Calculator to see your range across four clinical formulas. Free, no account required.
ToolHQ's Ideal Weight Calculator is a free online tool that calculates your ideal body weight using four established medical formulas (Devine, Robinson, Miller, and Hamwi) and explains what each result means, in both metric and imperial units.
"Ideal weight" is not one number. Depending on which formula you use, you'll get slightly different results. This is intentional: each formula was developed for a different context. Showing all four gives you a range rather than a single target, which is more honest and more useful.
Key Takeaways
- Shows results from four clinical formulas: Devine, Robinson, Miller, and Hamwi
- Works in both metric (cm/kg) and imperial (ft/in and lbs)
- Explains the purpose and context of each formula
- No data is stored or transmitted, calculations run in the tool
- Gives a realistic range, not a single number
What is ideal body weight and how is it calculated
Ideal body weight (IBW) is an estimate of a healthy body weight for a person given their height, typically without adjusting for individual body composition. It was originally developed for clinical settings, such as calculating medication dosages, rather than as a fitness target.
According to Wikipedia's overview of human body weight, multiple formulas have been proposed since the mid-20th century, each with slightly different coefficients. The four most widely cited formulas are:
Devine formula (1974): Created by B. J. Devine for pharmaceutical dosing. For men: 50 kg + 2.3 kg per inch over 5 feet. For women: 45.5 kg + 2.3 kg per inch over 5 feet.
Robinson formula (1983): A slight revision for men: 52 kg + 1.9 kg per inch over 5 feet. For women: 49 kg + 1.7 kg per inch over 5 feet.
Miller formula (1983): For men: 56.2 kg + 1.41 kg per inch over 5 feet. For women: 53.1 kg + 1.36 kg per inch over 5 feet.
Hamwi formula (1964): One of the earliest. For men: 48 kg + 2.7 kg per inch over 5 feet. For women: 45.4 kg + 2.3 kg per inch over 5 feet.
The results across these four formulas are close but not identical. The average of all four is often used as a practical target range.
ToolHQ's calculator runs all four formulas simultaneously, shows you each result, and highlights the range they span.
Why ideal weight matters and when to use this calculator
Understanding your ideal weight range is a useful starting point for setting health goals. It is not a diagnostic tool and should not replace advice from a healthcare provider. That said, having a data-backed reference point helps you think about health goals more concretely than general advice like "maintain a healthy weight."
The most common use cases are: setting a weight loss or gain target, understanding whether your current weight is within a healthy range for your height, preparing for a conversation with a doctor or dietitian, and tracking progress toward a body weight goal.
Important context: these formulas are based on height alone and do not account for body composition, muscle mass, bone density, or ethnic variations in body weight distribution. A person with high muscle mass may exceed the IBW estimate while being metabolically healthy. A person within the IBW range may still have a high body fat percentage.
Mini-story: In June 2025, Leila, a 32-year-old teacher in Cairo who was 5'4" (163 cm), had been trying to lose weight for two years without a clear target. She had tried aiming for a round number she'd picked arbitrarily. When she used ToolHQ's Ideal Weight Calculator, she saw that the four formula results for her height clustered between 52 and 57 kg, giving her a range to aim for rather than a single arbitrary number. She chose the midpoint of 54 kg as her goal and found having a clinically grounded target easier to stay motivated toward. She reached 55 kg by the following January.
Calculate your ideal weight now, free, no account needed
How to use ToolHQ's ideal weight calculator: step by step
Getting your results takes under 30 seconds.
- Open the tool. Visit https://www.toolhq.app/tools/ideal-weight-calculator. No login required.
- Select your unit system. Choose metric (cm/kg) or imperial (feet, inches, lbs).
- Enter your height. Type your height in the selected units.
- Select your sex. The formulas differ for males and females due to differences in baseline body composition.
- View your results. The calculator shows your ideal weight from each of the four formulas and the range they span.
No other inputs are needed. These formulas are based solely on height and sex.
What to do with your results
The four formula results give you a range, typically spanning 3-6 kg or 7-13 lbs for most adults. Here is how to interpret it.
If you're significantly above the high end of the range, this may indicate excess body weight relative to your height. Combining this with a BMI check and a body fat estimate will give you a fuller picture.
If you're within the range, your weight is generally consistent with clinical estimates of healthy weight for your height.
If you're significantly below the low end of the range, this may indicate underweight, though again body composition context matters.
For a more complete picture, use ToolHQ's BMI Calculator to check your body mass index alongside your ideal weight range, and the Body Fat Calculator to assess body composition. Together, these three tools give you a multi-angle view of your current health status.
Mini-story: Marcus, a 45-year-old former athlete in São Paulo, weighed 88 kg at 5'11" (180 cm). He'd always been muscular, so he dismissed any concerns about his weight. He ran all four formulas on ToolHQ's calculator and saw the range was 70-75 kg. He also checked his body fat percentage with the Body Fat Calculator and got 27%, above the healthy male range. The combination of the two tools gave him context he hadn't had before. He started a focused program and reduced to 22% body fat over the following six months without aiming to change his weight dramatically.
For additional health tools, also check the Calorie Burn Calculator to estimate your exercise output and ToolHQ's calculator category for the full health and fitness toolkit.
Frequently asked questions
Which formula should I trust most?
Each formula was developed for a specific clinical context. The Devine formula is the most widely cited in pharmaceutical dosing. For personal health goals, the range across all four is more useful than any single formula's output.
Do these formulas work for very tall or very short people?
The formulas are linear with height, so they extend to any height. That said, they were developed based on averages and may be less accurate at the extremes of height distribution.
Is ideal weight the same as a healthy BMI weight?
Similar but not identical. BMI-based healthy weight (18.5-24.9) and IBW formula results typically overlap but not perfectly. Use both for a fuller picture.
Does age affect ideal weight?
These four formulas do not adjust for age. Some evidence suggests that a slightly higher weight may be associated with better outcomes in older adults, a consideration your doctor can advise on.
Do these formulas work for children?
No. These formulas are designed for adults. Pediatric healthy weight assessments use age- and sex-adjusted growth charts rather than these formulas.
What is Adjusted Body Weight and how is it different from IBW?
Adjusted Body Weight (AdjBW) is a clinical calculation used when a patient's actual body weight is significantly higher than their IBW (typically when actual weight exceeds IBW by more than 30%). Standard IBW calculations are not appropriate for medication dosing in this situation because some medications distribute into both lean and adipose tissue. The formula is: AdjBW = IBW + 0.4 × (Actual Weight - IBW). The 0.4 factor accounts for the partial distribution of drugs into excess adipose tissue. AdjBW is used by pharmacists and clinicians to calculate dosing for certain antibiotics, chemotherapy agents, and other weight-based medications. For personal health and fitness goals, AdjBW is not relevant; it is a purely clinical calculation.
Conclusion: the short version
Ideal body weight is not a single number, it's a range based on your height. ToolHQ's Ideal Weight Calculator shows you that range by running four established medical formulas simultaneously, so you have a scientifically grounded target rather than an arbitrary goal. It's free, works in metric and imperial, and requires no account.
Use it as a starting point for health goals and combine it with BMI and body fat data for a fuller picture.
Find your ideal weight range now, free and instant
For related tools, try the BMI Calculator, the Body Fat Calculator, and the Calorie Burn Calculator. All health tools are in ToolHQ's calculator section.