Ideal Weight Calculator

An ideal weight calculator estimates the target weight range considered healthy for your height, sex, and frame size. It is used by individuals setting weight loss or gain goals, healthcare professionals giving weight management advice, and anyone wanting a reference point beyond BMI alone. Several formulas exist, each with slightly different underlying assumptions, and the calculator typically presents multiple estimates alongside a healthy BMI-based range.

How to Use the Ideal Weight Calculator

1. Enter your height in centimetres (or feet and inches).
2. Select your sex (male or female).
3. Optionally select your frame size (small, medium, or large), which some formulas use to adjust the estimate.
4. The calculator applies the most widely validated formulas (Devine, Robinson, Miller, and Hamwi) and shows results from each.
5. It also displays the weight range corresponding to a BMI of 18.5 to 24.9, which represents the standard healthy weight band for your height.

The Formula

Several formulas are commonly used. All provide the ideal weight in kilograms based on height.

Devine Formula (1974, originally for drug dosing): Men: 50 kg plus 2.3 kg for each inch over 5 feet Women: 45.5 kg plus 2.3 kg for each inch over 5 feet

Robinson Formula (1983): Men: 52 kg plus 1.9 kg for each inch over 5 feet Women: 49 kg plus 1.7 kg for each inch over 5 feet

Miller Formula (1983): Men: 56.2 kg plus 1.41 kg for each inch over 5 feet Women: 53.1 kg plus 1.36 kg for each inch over 5 feet

Hamwi Formula (1964): Men: 48 kg plus 2.7 kg for each inch over 5 feet Women: 45.5 kg plus 2.2 kg for each inch over 5 feet

BMI-based range: weight range for BMI 18.5 to 24.9 given the individual's height.

Real-World Example

A woman is 165 cm (5 feet 5 inches) tall.

Inches over 5 feet: 5 inches.

Devine: 45.5 plus (2.3 multiplied by 5) = 45.5 plus 11.5 = 57 kg Robinson: 49 plus (1.7 multiplied by 5) = 49 plus 8.5 = 57.5 kg Miller: 53.1 plus (1.36 multiplied by 5) = 53.1 plus 6.8 = 59.9 kg Hamwi: 45.5 plus (2.2 multiplied by 5) = 45.5 plus 11 = 56.5 kg

The estimates cluster between 57 kg and 60 kg.

BMI-based healthy range: at 165 cm, healthy weight spans BMI 18.5 to 24.9. Lower bound: 18.5 multiplied by (1.65)^2 = 18.5 multiplied by 2.7225 = 50.4 kg Upper bound: 24.9 multiplied by 2.7225 = 67.8 kg

The healthy weight range for this woman is approximately 50 kg to 68 kg, with the formula estimates suggesting a midpoint around 57 to 60 kg.

Limitations and Context

No single number represents a universally correct "ideal" weight. The formulas above were developed for clinical use in drug dosing and are based on population averages. They do not account for muscle mass, bone density, age, or ethnicity, all of which meaningfully affect what weight is healthy for a specific individual.

Athletes and people with high muscle mass will typically have an "ideal weight" from these formulas that appears underweight relative to their actual healthy composition. Conversely, older adults who have lost muscle mass may achieve a weight within formula targets while having an unhealthy body composition.

Frame size adds a layer of nuance. Wrist circumference relative to height is often used to estimate frame size (small, medium, or large). People with larger, denser bone structures naturally weigh more at the same height and should use the upper end of healthy weight ranges.

Ethnicity also matters. Research consistently shows that South Asian and East Asian populations face increased metabolic risk at lower BMIs and body weights than European populations. The WHO suggests alternative BMI thresholds for Asian groups, which would shift the healthy weight range downward for these individuals.

Reference Table: Ideal weight by four published formulas

Four formulas for men at three heights, all measured from 60 inches with a per-inch increment. The formulas disagree by 2 to 4 kg, which is why a range is more honest than a single number. At 170 cm the estimates span 65.2 to 66.7 kg.

Worked Example on Screen

The capture below shows Ideal Weight Calculator after the inputs were entered, with the result on screen. Enter the same values to reproduce it.

Captured from solved.tools on 10 September 2026.

Frequently Asked Questions

Is the ideal weight the same as a healthy weight? Not exactly. "Ideal weight" from a formula represents a statistical estimate based on population data. "Healthy weight" is more broadly defined as any weight at which an individual has normal metabolic health markers (blood pressure, blood sugar, cholesterol, etc.) without symptoms of disease. Some individuals are metabolically healthy at weights above their "ideal," while others have poor metabolic health within the formula's range.

Do ideal weight formulas apply to children? No. All the formulas above are designed for adults. For children and teenagers, weight assessment uses BMI-for-age percentile charts that account for changing body composition through puberty. A paediatrician or GP can interpret these charts in the context of a child's individual growth trajectory.

How does muscle mass affect my ideal weight? The ideal weight formulas do not distinguish between muscle and fat. A person with a high proportion of lean muscle mass will weigh more than these formulas predict for their height, yet may be in excellent health. For muscular individuals, body fat percentage is a more relevant target than total body weight. A male bodybuilder might be healthy at 90 kg with 10% body fat, well above what any formula would suggest for their height.

Should I aim to reach my ideal weight calculated by the formula? Not necessarily. Use the formula as a rough orientation point rather than a fixed target. Work with your GP or a registered dietitian to set a personalised weight goal based on your health history, body composition, metabolic markers, and what is realistic and sustainable for you. A 5% to 10% reduction in body weight from an overweight starting point produces significant health benefits even if you do not reach the formula's target.

Understanding the Ideal Weight Calculator

The Ideal Weight Calculator is one of the most-requested tools in the ideal weight category because it condenses a calculation that would otherwise require manual work, a spreadsheet, or a specialist program into a single input-and-output step. whether you are a student, a professional, or a curious learner, the Ideal Weight Calculator is designed to deliver a quick and trustworthy answer without forcing you to install anything or sign up for an account. Behind the scenes, the Ideal Weight Calculator applies well-established mathematical or scientific formulas to the values you provide. the aim of Ideal Weight Calculator is to remove the friction of hand calculation while still showing you the underlying method, so you can confidently interpret the result. Every calculation is performed locally in your browser, which means your inputs never leave your device.

When Should You Use the Ideal Weight Calculator?

Use the Ideal Weight Calculator whenever you need a quick, reliable answer that fits the tool's scope. Common situations for the Ideal Weight Calculator include homework problems, workplace tasks, financial planning, fitness or health tracking, and everyday curiosity. If the Ideal Weight Calculator answer will be used for a decision that has legal, medical, or financial consequences, treat the result as a starting point and verify it with a qualified professional. The Ideal Weight Calculator is free to use, requires no sign-up, and works on any device with a modern browser. You can run the Ideal Weight Calculator as many times as you like, change the inputs, and compare results side by side.

Common Inputs and How to Choose Them

Most Ideal Weight Calculator problems revolve around a small set of inputs.

• your height in centimetres (or feet and inches) is usually the first value to pin down for the Ideal Weight Calculator.
• your sex (male or female) sets the context the Ideal Weight Calculator needs for a sensible result.
• Optionally select your frame size (small, medium, or large), which some formulas use to adjust the estimate refines the Ideal Weight Calculator output where the data is available. Identifying the right values is the most important step for the Ideal Weight Calculator, because the answer is only as accurate as the data you put in. If a value is unknown, prefer a conservative estimate over a guess when using the Ideal Weight Calculator.

How to Interpret the Result

The numerical answer from the Ideal Weight Calculator alone is rarely the whole story. Read the units, the precision, and any warnings shown alongside the Ideal Weight Calculator result. Understanding the path from inputs to output in the Ideal Weight Calculator makes it easier to spot errors, communicate the result to others, and reuse the method for related problems in the future.

Worked Examples

A typical Ideal Weight Calculator run takes reasonable inputs, produces a sensible answer, and returns it in a single click. Example: A woman is 165 cm (5 feet 5 inches) tall. Inches over 5 feet: 5 inches. Devine: 45.5 plus (2.3 multiplied by 5) = 45.5 plus 11.5 = 57 kg Robinson: 49 plus (1.7 multiplied by 5) = 49 plus 8.5 = 57.5 kg Miller: 53.1 plus (1.36 multiplied by 5) = 53.1 plus 6.8 = 59.9 kg Hamwi: 45.5 plus (2.2 multiplied by 5) = 45.5 plus 11 = 56.5 kg The estimates cluster between 57 kg and 60 kg. BMI-based healthy ran

Common Mistakes to Avoid

Common mistakes with the Ideal Weight Calculator:

• Mixing up units (for example, entering one unit when the Ideal Weight Calculator expects another).
• Forgetting to convert percentages to decimals or vice versa where the Ideal Weight Calculator formula requires it.
• Using a snapshot value that no longer reflects reality for the Ideal Weight Calculator, especially for time-sensitive inputs like prices, rates, or counts.
• Rounding intermediate steps too early and then carrying the rounded value forward in the Ideal Weight Calculator.
• Treating the Ideal Weight Calculator as a substitute for professional advice when the decision is high-stakes.

Limitations and Assumptions

No calculator is a perfect model of reality, and the Ideal Weight Calculator is no exception. The Ideal Weight Calculator makes simplifying assumptions to keep the math tractable: it ignores rare cases, applies default values where inputs are missing, and uses formulas that suit the typical situation rather than the exotic one. When your situation falls outside the typical case, the Ideal Weight Calculator result may drift further from the truth. If you need a more precise answer than the Ideal Weight Calculator provides, the next step is usually a specialist, a more detailed reference, or a domain-specific tool.

Related Tools and References

For more depth on the Ideal Weight Calculator topic, consult textbooks, academic papers, or reputable online resources. Reputable sources for the Ideal Weight Calculator include government statistics agencies, university extension services, and peer-reviewed journals. Wikipedia is a useful starting point for definitions and formulas behind the Ideal Weight Calculator, but always follow the citations to the original source before relying on a number. If you find that you need the same Ideal Weight Calculator calculation repeatedly, consider writing down the inputs and the result in a note so you can build a personal record over time.

Quick Reference

• Free to use: yes, no sign-up required.
• Privacy: all calculations run locally in your browser.
• Units: metric and imperial supported where applicable; check the input labels.
• Speed: instant, no page reload.
• Mobile friendly: yes, works on phones and tablets.
• Offline: once the page has loaded, the calculation continues to work without a network connection.

References - General-purpose math references such as Wolfram MathWorld and Khan Academy for foundational formulas.

• Wikipedia articles on the relevant topic, with citations to primary sources, cover the Ideal Weight Calculator background.
• Peer-reviewed journals and textbooks give the most rigorous treatments of the Ideal Weight Calculator method.Tools/tools/calculator) - Percentage Calculator - Unit Converter

Also try these free tools:

• BMI Calculator
• Body Fat Calculator
• BMR Calculator