Ideal Weight Calculator
What Should I Weigh for My Height?
Enter your height, gender, and age to instantly find your ideal body weight using 4 trusted medical formulas. Includes BMI healthy range, WhatsApp share card, and free PDF report.
Needle shown only if you entered your current weight above.
| Formula | Men | Women |
|---|---|---|
| Devine (1974) | 50 kg + 2.3 per inch over 5ft | 45.5 kg + 2.3 per inch over 5ft |
| Robinson (1983) | 52 kg + 1.9 per inch over 5ft | 49 kg + 1.7 per inch over 5ft |
| Miller (1983) | 56.2 kg + 1.41 per inch over 5ft | 53.1 kg + 1.36 per inch over 5ft |
| Hamwi (1964) | 48 kg + 2.7 per inch over 5ft | 45.5 kg + 2.2 per inch over 5ft |
All four formulas are averaged to give a single balanced ideal weight estimate. The BMI healthy range (18.5 to 24.9) is calculated separately using your height.
What Is Ideal Body Weight?
Originally developed to help clinicians calculate appropriate medication dosages for patients rather than as fitness targets, ideal body weight formulas have been widely used in clinical medicine for decades. The Devine formula alone is still used in calculating drug dosages, ventilator settings, and nutritional support requirements in hospitals worldwide. When combined with the broader BMI healthy range, they give a useful double reference point for anyone assessing their weight.
Use this calculator alongside our BMI Calculator and Body Fat Calculator for the most complete picture of your weight and body composition health.
The 4 Medical Formulas Explained
Devine Formula (1974)
Developed by Dr. B.J. Devine specifically for clinical drug dosing, particularly for medications where dosing needs to be based on lean body weight rather than total body weight. It remains the most widely cited ideal body weight formula in clinical medicine. For men: 50 kg plus 2.3 kg per inch over 5 feet. For women: 45.5 kg plus 2.3 kg per inch over 5 feet.
Robinson Formula (1983)
Developed as a refinement of Devine's approach using a larger, more diverse patient dataset. The Robinson formula adjusts the per-inch increment slightly and generally produces a marginally higher ideal weight estimate than Devine's version. For men: 52 kg plus 1.9 kg per inch over 5 feet. For women: 49 kg plus 1.7 kg per inch over 5 feet.
Miller Formula (1983)
Introduced the same year as Robinson's version, the Miller formula uses a different base weight and increment, generally yielding estimates closer to real-world average body weights than Devine or Robinson for many height ranges. For men: 56.2 kg plus 1.41 kg per inch over 5 feet. For women: 53.1 kg plus 1.36 kg per inch over 5 feet.
Hamwi Formula (1964)
One of the oldest formulas still in common use, originally developed by Dr. George Hamwi for estimating appropriate caloric needs in diabetic patients. It tends to produce a slightly lower ideal weight estimate than the other three formulas. For men: 48 kg plus 2.7 kg per inch over 5 feet. For women: 45.5 kg plus 2.2 kg per inch over 5 feet.
| Formula | Year | Men Base | Women Base | Per Inch |
|---|---|---|---|---|
| Devine | 1974 | 50 kg | 45.5 kg | 2.3 kg |
| Robinson | 1983 | 52 kg | 49 kg | 1.9 / 1.7 kg |
| Miller | 1983 | 56.2 kg | 53.1 kg | 1.41 / 1.36 kg |
| Hamwi | 1964 | 48 kg | 45.5 kg | 2.7 / 2.2 kg |
Ideal Weight vs Healthy BMI Range -- What Is the Difference?
Ideal body weight formulas give a single estimated number based on height and gender alone. They were originally intended for clinical drug dosing, not as personal fitness targets. For example, at 170cm a woman's ideal weight averages approximately 59-61 kg across the four formulas.
Healthy BMI range gives a broader window. Any weight that keeps your Body Mass Index between 18.5 and 24.9 is generally considered healthy by the World Health Organization. For a 170cm woman, this range spans approximately 53-72 kg -- a much wider window that recognises individual variation in body composition, frame size, and muscle mass.
Ideal Weight by Height -- Quick Reference (Average of 4 Formulas)
| Height | Men Ideal Weight | Women Ideal Weight | Healthy BMI Range (both) |
|---|---|---|---|
| 155 cm (5ft 1in) | approx 57 kg (126 lb) | approx 52 kg (115 lb) | 44-60 kg |
| 160 cm (5ft 3in) | approx 61 kg (134 lb) | approx 55 kg (122 lb) | 47-64 kg |
| 165 cm (5ft 5in) | approx 65 kg (143 lb) | approx 58 kg (128 lb) | 50-68 kg |
| 170 cm (5ft 7in) | approx 68 kg (150 lb) | approx 61 kg (135 lb) | 53-72 kg |
| 175 cm (5ft 9in) | approx 72 kg (159 lb) | approx 65 kg (143 lb) | 57-76 kg |
| 180 cm (5ft 11in) | approx 76 kg (168 lb) | approx 68 kg (150 lb) | 60-81 kg |
| 185 cm (6ft 1in) | approx 80 kg (176 lb) | approx 72 kg (159 lb) | 63-85 kg |
What These Formulas Cannot Tell You
- Muscle mass: Athletes and people who strength train often weigh significantly more than formula estimates while having very low body fat. Check your body fat percentage for a more accurate picture if you are muscular
- Bone frame size: A larger frame naturally and healthily carries more weight than a smaller frame at the same height
- Abdominal fat distribution: Where fat is stored matters as much as total weight. Check your waist-to-height ratio and waist-to-hip ratio to assess abdominal fat risk independently of total weight
- Age-related body composition changes: Muscle mass typically declines with age even at a stable weight, meaning the same weight can represent different body compositions at different life stages. Check your biological age
- Metabolic health markers: Blood pressure, blood sugar, and cholesterol tell you far more about your health risk than weight alone. Check these with our Blood Pressure Checker, Blood Sugar Checker, and Cholesterol Checker
- Pregnancy: These formulas were not designed for and do not apply during pregnancy
How to Reach Your Ideal Weight Sustainably
- Know your daily calorie needs: Use our Weight Loss Calculator to find the right calorie target for your pace of weight change
- Aim for gradual change: Approximately 0.5 to 1 kg per week is a sustainable, evidence-supported pace for most people. Faster loss risks muscle loss and nutrient deficiency
- Track your macros: Adequate protein preserves muscle while in a calorie deficit. Use our Macro Calculator to set your daily protein, carb, and fat targets
- Combine cardio and strength training: Cardio burns calories; strength training preserves and builds muscle, keeping your metabolism higher during fat loss. See our Calorie Burned Calculator
- Monitor water intake: Adequate hydration supports metabolism and appetite control. Check your target with our Water Intake Calculator
- Prioritise sleep: Poor sleep raises ghrelin (hunger hormone) and lowers leptin (satiety hormone), making weight management significantly harder
- Track trends, not daily fluctuations: Day-to-day weight shifts are mostly water and digestive contents. Track weekly averages over 4-6 weeks for meaningful data
