Ideal Weight Calculator
Calculate Ideal Weight
Understanding healthy weight: ranges, formulas and practical guidance
An “ideal” or “healthy” weight is not a single number — it’s a range that depends on height, age, sex and body composition. This calculator uses internationally established approaches to provide a balanced, transparent result: a healthy weight range (based on BMI thresholds commonly used for adults), plus multiple well-known formulae used historically in clinical practice. Presenting a range — not a single target number — reduces anxiety and reflects the natural variation in body shapes and compositions.
For adults (age 18 and over) we present the healthy weight range defined by BMI values of 18.5 to 24.9. BMI is weight divided by height squared (kg/m²) and is widely used for population-level assessment. While BMI alone doesn’t tell the complete story (muscle mass, bone density, and fat distribution are not captured), it remains a simple and useful starting point for deciding whether a person falls in a broadly “healthy” zone for their height.
To build credibility and transparency, this tool also calculates three classic clinical formulas side-by-side: Devine, Hamwi and Robinson. These formulas estimate an “ideal” weight using height (in inches over 5 feet) and sex. Clinicians often use these values for dosing, nutritional planning, and quick reference. Seeing multiple methods together helps users understand that different approaches yield slightly different but related results — and that individual goals may differ from method outputs.
Children and teenagers (starting at age 3) require a different approach: healthy weight is assessed using BMI-for-age percentiles rather than the adult BMI cutoffs. Growth charts from health authorities are the authoritative method for children. This calculator computes BMI for children and points you to the official growth-chart resources (for exact percentiles). For convenience it also offers an approximate healthy weight band for younger users — but exact interpretation for children should rely on pediatric growth charts and professional advice.
A short note on safety and use: results here are estimates and do not replace individualized medical evaluation. If you or your child have rapid weight change, a complex medical history, or concerns about growth or nutrition, contact a healthcare professional for personalized assessment. That approach keeps guidance both responsible and useful: this tool helps with planning and understanding, but clinical decisions belong to trained providers.