Ideal Weight Calculator
Use this free ideal weight calculator to find your healthy target weight based on your height, sex, and body frame. This tool uses four clinically established formulas — Hamwi, Devine, Robinson, and Miller — to give you a reliable weight range rather than a single arbitrary number. Whether you’re setting a weight loss goal or simply want a health benchmark, this calculator gives you a medically grounded starting point.
Ideal Weight Calculator
How to Use the Ideal Weight Calculator
- Select your sex (male or female)
- Enter your height in cm or feet and inches
- Optionally select your body frame size (small, medium, or large)
- Click Calculate to see your ideal weight range across four formulas
What Is Ideal Body Weight?
Ideal body weight (IBW) is the weight range considered most appropriate for your height and sex, based on statistical health data. It is widely used in clinical settings to calculate medication dosages, anaesthesia requirements, nutritional needs, and fitness benchmarks. While no single number fits every person perfectly — body composition, bone density, and muscle mass all vary — IBW provides a useful evidence-based reference point.
IBW is different from your BMI healthy weight range, though the two overlap significantly. Use our BMI calculator alongside this tool for a more complete picture of where your weight sits relative to health guidelines.
The Four Ideal Weight Formulas Explained
| Formula | Year | Originally Used For | Men (5’7″ / 170cm) | Women (5’7″ / 170cm) |
|---|---|---|---|---|
| Hamwi | 1964 | Insulin dosing in diabetes patients | 72.7 kg | 63.6 kg |
| Devine | 1974 | Drug dosage calculations | 71.0 kg | 63.5 kg |
| Robinson | 1983 | General clinical nutrition | 68.0 kg | 61.4 kg |
| Miller | 1983 | General clinical use | 67.9 kg | 62.0 kg |
All four formulas were developed for clinical use, not for general fitness or aesthetic goals. The range across formulas (67–73 kg for a 5’7″ man) reflects legitimate variation — your healthy ideal weight sits somewhere within this range depending on your individual build.
Ideal Weight by Height — Reference Table
| Height | Ideal Weight Range (Men) | Ideal Weight Range (Women) | Healthy BMI Weight Range |
|---|---|---|---|
| 5’0″ (152 cm) | 48–58 kg | 43–53 kg | 43–57 kg |
| 5’2″ (157 cm) | 52–62 kg | 47–57 kg | 45–59 kg |
| 5’4″ (163 cm) | 56–67 kg | 51–62 kg | 49–65 kg |
| 5’6″ (168 cm) | 60–72 kg | 54–66 kg | 52–70 kg |
| 5’8″ (173 cm) | 64–77 kg | 58–71 kg | 55–74 kg |
| 5’10” (178 cm) | 67–81 kg | 61–74 kg | 59–79 kg |
| 6’0″ (183 cm) | 73–87 kg | 66–79 kg | 62–84 kg |
| 6’2″ (188 cm) | 78–93 kg | 71–85 kg | 66–89 kg |
How Body Frame Size Affects Ideal Weight
People with larger bone structures naturally weigh more at the same height. A simple way to estimate your frame size is the wrist measurement method:
- Men: Wrist under 16 cm = small frame; 16–17 cm = medium frame; over 17 cm = large frame
- Women: Wrist under 14 cm = small frame; 14–15 cm = medium frame; over 15 cm = large frame
Large-frame individuals can reasonably target the upper end of their IBW range. Small-frame individuals should aim toward the lower end. Medium frame is the standard assumption when no frame adjustment is made.
Ideal Weight vs BMI — What’s the Difference?
Both measures aim to define a healthy weight, but they approach it differently:
- BMI gives a range (e.g. 55–74 kg for a 5’6″ person) based on the healthy BMI band of 18.5–24.9
- IBW gives a target point (or narrow range) based on statistical health data for your height and sex
- Neither accounts for muscle mass — an athlete with high muscle mass may be heavier than their IBW while having very low body fat
For the most complete picture of your health, use IBW alongside our BMI Calculator and Body Fat Calculator.
What This Means for You
Your ideal weight result is a guideline, not a strict target. Here’s how to use it practically:
- If you’re above your IBW range: A modest calorie deficit combined with regular activity can bring you closer over time. Use our calorie calculator to find your daily target
- If you’re within your IBW range: Focus on body composition rather than weight — building muscle and reducing fat percentage is more meaningful than chasing a specific number
- If you’re below your IBW range: Consider speaking to your GP, particularly if weight loss was unintentional. Increasing calorie-dense, nutritious foods can support healthy weight gain
- If you’re muscular: Your ideal weight may naturally sit above the IBW formula result — this is expected and healthy. Body fat percentage is a more relevant metric for you
Ideal Weight Calculator FAQ
How accurate is an ideal weight calculator?
For average adults with typical body composition, IBW formulas are useful within about ±5 kg. They become less accurate for athletes with high muscle mass, elderly individuals with reduced muscle, or people with unusual height-to-weight proportions. The range across multiple formulas (shown in this calculator) is more meaningful than any single formula result.
Is ideal weight the same for men and women?
No — women naturally carry more body fat and have less muscle mass and denser bone structures relative to men at the same height, which is reflected in the lower IBW values for women. At 5’7″, a woman’s ideal weight is typically 61–64 kg compared to 68–73 kg for a man of the same height.
Should I aim to reach my exact ideal weight?
Not necessarily. The IBW is a clinical reference point, not a personal aspiration target. Many healthy, fit people sit 5–10 kg above their IBW due to muscle mass. Focus on how you feel, your energy levels, your fitness metrics, and your body fat percentage rather than a single weight number.
Which IBW formula is most accurate?
Research suggests no single formula is definitively superior — they were all developed for specific clinical contexts. The Devine formula is most widely used in medical settings for drug dosage. For general purposes, the average of all four formulas gives a reasonable consensus estimate, which is what this calculator presents.
Does age affect ideal weight?
Standard IBW formulas don’t adjust for age. In practice, older adults tend to have more body fat and less muscle at the same weight as younger adults, so body fat percentage becomes increasingly important with age. Some health authorities suggest that slightly higher weight (within the overweight BMI band) may actually be protective for older adults — a phenomenon known as the “obesity paradox.”
Related Calculators
- BMI Calculator — Check your Body Mass Index and healthy weight range
- Body Fat Calculator — Estimate body fat percentage using body measurements
- Calorie Calculator — Get your daily calorie target for weight loss or gain
- BMR Calculator — Find out how many calories your body burns at rest
- Water Intake Calculator — Get your personalised daily hydration recommendation