How to Use the Ideal Weight Calculator

Enter your height — in feet/inches or centimetres.
Select your gender — ideal weight formulas differ slightly between males and females due to differences in muscle mass and bone density.
Read the ideal weight range — the calculator shows results from multiple medical formulas (Devine, Robinson, Miller, Hamwi) alongside the healthy BMI range.
Consider your frame size — small-framed individuals should target the lower end of the range, large-framed the upper end.
Use as a guide, not a goal — ideal weight ranges are population averages. Athletic individuals with high muscle mass are often 'overweight' by these measures while being exceptionally healthy.

⚠️ Important context: Ideal weight formulas were developed in the 1960s–70s for insurance actuarial purposes — not as health targets. They do not account for muscle mass, bone density, age, or ethnicity. A muscular athlete and a sedentary person of the same height get the same 'ideal weight' despite dramatically different body compositions and health profiles.

Understanding Ideal Weight Metrics

📐 Devine Formula

Most widely used in clinical settings. Male: 50 + 2.3kg per inch above 5 feet. Female: 45.5 + 2.3kg per inch above 5 feet. Developed for medication dosing calculations — gives a single number rather than a range.

📊 Healthy BMI Range

BMI 18.5–24.9 corresponds to a weight range for any height. A 175cm person: healthy weight = 56.7–76.3 kg. This range is broader than formula-based 'ideal weights' and more appropriate for most people.

🏋️ Muscle Mass Factor

BMI and ideal weight formulas cannot distinguish muscle from fat. Elite athletes often have BMIs of 27–30 (technically 'overweight') with very low body fat percentages. Conversely, 'normal weight obesity' — normal BMI with high body fat — is a recognised health risk.

📏 Frame Size

Wrist circumference relative to height indicates frame size. Small frame = lower end of ideal weight range. Medium frame = middle. Large frame = upper end. Frame size accounts for differences in bone density and structure that affect healthy weight.

🌍 Ethnic Variations

Standard ideal weight ranges were developed primarily from Caucasian populations. Asian populations have higher health risks at lower BMIs — many health organisations recommend lower thresholds for Asian populations. The WHO has proposed adjusted BMI cut-offs for Asian populations.

⚖️ Body Composition Priority

For health and appearance, body fat percentage is more meaningful than scale weight. A 175cm man at 80kg with 15% body fat is healthier and looks better than the same man at 72kg with 28% body fat — even though 72kg is closer to 'ideal weight.'

Setting Realistic Weight Goals

Weight vs body composition

The most common mistake in weight management is focusing on scale weight rather than body composition. During resistance training programs, people often lose fat while gaining muscle — resulting in little or no scale weight change despite significant body transformation. Progress photos, body measurements, and how clothes fit are often more informative than scale weight during body recomposition.

Setting a realistic target

Rather than targeting a specific 'ideal weight' number, target a body fat percentage: 10–18% for men (athletic to healthy), 18–28% for women (athletic to healthy). These targets are achievable, health-promoting, and independent of muscle mass. They also provide clearer guidance on diet and exercise intensity needed to reach the goal.

Weight maintenance is the hardest part

Research consistently shows that reaching a goal weight is far easier than maintaining it. Approximately 80% of people who lose significant weight regain most of it within 5 years. Sustainable weight management requires permanent lifestyle changes — not temporary diets. Building habits you can maintain indefinitely matters more than reaching an 'ideal' number quickly.

🎯 Healthier goal framework: Instead of 'I want to weigh X kg,' try 'I want to lose 1 inch from my waist' or 'I want to run 5km without stopping' or 'I want to do 10 pull-ups.' Performance and measurement goals create better habits and produce better body composition results than scale-weight targets.

Frequently Asked Questions

Why do different formulas give different results?

Ideal weight formulas were developed at different times with different populations. Hamwi (1964) was created for clinical use. Devine (1974) was developed for drug dosing. Robinson (1983) and Miller (1983) updated the earlier formulas. None is universally accepted — the average of all four gives a more reliable estimate.

Is ideal weight the same as healthy weight?

Not exactly. Ideal weight formulas give a single target number. Healthy weight is a range based on BMI (18.5–24.9). BMI-based range is generally considered more clinically useful because it accounts for the fact that healthy weight exists on a spectrum, not a single point.

Should I use my ideal weight as my goal?

Ideal weight is a rough guideline, not a prescription. Factors like muscle mass, bone density, age, and fitness level matter more than the number on the scale. Athletes often weigh more than 'ideal' due to muscle mass. Focus on body fat percentage and fitness markers over absolute weight.