Ideal Weight Calculator

About the Ideal Weight Calculator

An ideal weight calculator estimates the weight range that is considered healthy and optimal for your height, sex, and frame size. "How much should I weigh?" is one of the most searched health questions globally, reflecting widespread desire for a concrete weight goal to aim for. Our free ideal weight calculator computes results using four of the most widely used and clinically referenced formulas: Hamwi (used by US military and healthcare), Devine (used in pharmaceutical dosing calculations), Miller, and the BMI-based healthy weight range (18.5–24.9 BMI). It also shows the ideal weight according to body fat percentage targets for your sex — often a more meaningful metric than scale weight alone for athletic or muscular individuals. Understanding what constitutes a healthy weight range for your specific height helps you set realistic, evidence-based fitness goals instead of chasing arbitrary numbers influenced by social media or unrealistic beauty standards. The calculator presents results as a range, not a single number, because healthy weight varies based on individual body composition, bone density, muscle mass, and genetics.

How It Works

The four main ideal weight formulas (for height in inches above 5 feet, using H = height inches minus 60): Hamwi method: Men: 106 lbs + 6 lbs per inch over 5 feet. Women: 100 lbs + 5 lbs per inch over 5 feet. Example: 5 ft 10 in male: 106 + (10 x 6) = 166 lbs. Devine formula: Men: 50 kg + 2.3 kg per inch over 5 feet. Women: 45.5 kg + 2.3 kg per inch over 5 feet. Miller formula: Men: 56.2 kg + 1.41 kg per inch over 5 feet. Women: 53.1 kg + 1.36 kg per inch over 5 feet. BMI method (18.5–24.9 range): Min weight = 18.5 x height(m)^2; Max weight = 24.9 x height(m)^2. For a 178 cm male: 18.5 x 3.168 = 58.6 kg (129 lbs) to 24.9 x 3.168 = 78.9 kg (174 lbs). The formulas typically agree within 5-10 lbs but differ because they were derived from different population samples and time periods.

Tips & Best Practices

• ✓Ideal weight is a range, not a single number. Biological variation in bone density, muscle mass, and frame size means a healthy weight for your height can span 20-30 lbs depending on your individual body composition.
• ✓Muscle mass dramatically affects ideal weight: a 5 ft 10 in male competitive bodybuilder might weigh 200 lbs at 8% body fat — far above any "ideal weight" formula but clearly healthy. Scale weight without body fat context is often misleading.
• ✓The BMI healthy weight range (18.5–24.9) is the most widely used clinical reference. For a 5 ft 5 in woman, this corresponds to approximately 111–149 lbs — a 38-pound range reflecting genuine biological variation.
• ✓Frame size adjustment: large-framed individuals can healthily weigh 10% above the formula result; small-framed individuals 10% below. Measure wrist circumference to estimate frame: women with wrist under 5.5 inches are small-framed; men with wrist under 6.5 inches are small-framed.
• ✓Weight and health are not perfectly correlated: research consistently shows that fitness level (cardiorespiratory fitness) predicts health outcomes better than weight alone. A fit person at the upper end of their ideal weight range is healthier than an unfit person at the lower end.
• ✓Children and teenagers have age- and sex-specific ideal weight ranges using BMI-for-age percentile charts — adult formulas do not apply during growth phases.
• ✓For body composition goals (looking and feeling fit rather than hitting a scale number), targeting a specific body fat percentage (12-17% for men, 20-25% for women for "fitness" category) is more meaningful than hitting a formula-derived weight.
• ✓Rapid weight loss targeting an "ideal weight" number causes muscle loss, hair loss, hormonal disruption, and metabolic adaptation. Sustainable approaches aim for 0.5–1 lb/week loss maximum.

Who Uses This Calculator

People beginning a weight management programme use the ideal weight calculator to set a realistic, evidence-based target weight rather than an arbitrary number. Healthcare providers use ideal body weight (IBW) formulas — particularly Devine — as a clinical reference for medication dosing calculations, anaesthesia dosing, and nutritional prescriptions in hospital settings. Personal trainers and fitness coaches use ideal weight ranges to help clients set realistic goals that account for body composition rather than just the scale number. Individuals struggling with body image use the calculator to understand that healthy weight is a range — and that their target does not need to be the absolute minimum of that range to be healthy. Parents track their children's growth against age-appropriate weight-for-height standards during paediatric appointments. Sports coaches use weight range information to help athletes in weight-class sports identify competitive weight classes that match their natural frame without requiring extreme cutting.