Health & Fitness
Ideal Weight Calculator
Calculate your ideal body weight based on your height, age, and gender using multiple validated formulas.
Reviewed by the calculator.uk.com Team · Last reviewed 3 July 2026 · Our methodology
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Related to Ideal Weight Calculator
The Ideal Weight Calculator uses multiple scientifically validated formulas to estimate your ideal body weight based on your height, gender, and age. Each formula takes into account different factors and has been developed through extensive research in the medical field.
The Four Main Formulas
1. Devine Formula (1974): Most widely used in clinical settings, particularly for drug dosing.
2. Robinson Formula (1983): Provides a more moderate estimate compared to other formulas.
3. Miller Formula (1983): Generally gives the highest estimates among the formulas.
4. Hamwi Formula (1964): One of the earliest and still widely referenced methods.
Each formula calculates ideal body weight using a base weight for your gender and adds a specific amount for each inch above base height (60 inches for men, 58 inches for women). The calculator then provides an average of all formulas to give you a balanced estimate.
The ideal weight results should be interpreted as general guidelines rather than strict targets. Your optimal weight can vary based on factors not included in these formulas, such as body composition, muscle mass, bone density, and overall health status.
Understanding the Range
The variation between different formulas (typically 5-10%) shows that ideal weight is not a single number but a range. The average of all formulas provides a balanced reference point, but you should consider this alongside other health indicators like BMI, body composition, and overall fitness level.
Remember that these calculations are based on statistical averages and traditional medical standards. They don't account for athletic build, age-related changes in body composition, or ethnic variations in body type. Use these results as one of many tools in assessing your healthy weight range.
1. Why do different formulas give different results?
Each formula was developed using different research populations and methodologies. The variations reflect the complexity of determining ideal weight and the diversity of human body types. This is why we provide multiple formulas and an average for a more comprehensive assessment.
2. Does muscle mass affect ideal weight calculations?
Yes, these formulas don't directly account for muscle mass. Athletes and individuals with high muscle mass may have a healthy weight above their calculated ideal weight, as muscle tissue is denser than fat tissue.
3. How often should I check my ideal weight?
For adults, ideal weight calculations don't change unless there's a change in height (which is rare in adulthood). However, it's good to monitor your actual weight regularly, typically every 1-2 weeks, while working towards your weight goals.
4. Should I aim for exactly my calculated ideal weight?
No, the calculated ideal weight is a reference point, not a strict target. A healthy weight can fall within a range of 5-10% above or below the calculated ideal weight, depending on various factors including body composition, fitness level, and overall health status.
5. What is the scientific source for this calculator?
This calculator applies four long-standing ideal-body-weight formulas from clinical and pharmacy literature: the Devine formula (1974), still commonly used for drug-dosing calculations; the Robinson (1983) and Miller (1983) formulas, later refinements using the same base-height-plus-increment approach; and the Hamwi formula (1964), one of the earliest such estimates, developed for use in nutrition and weight-management practice. Each formula adds a fixed increment per inch of height above a baseline, and because their exact original publication details vary across secondary sources, the calculator presents the average across all four as a general reference range rather than a single authoritative figure.