Ideal Weight Calculator
Calculate your ideal body weight using multiple medical formulas.
Ideal Weight Calculator – Find Your Ideal Body Weight Instantly
What Is an Ideal Weight Calculator?
An Ideal Weight Calculator is a free online health calculator that estimates the weight range considered healthy and optimal for your height and gender. Unlike the BMI calculator, which categorises your current weight, the Ideal Weight Calculator gives you a specific target weight to aim for based on clinically established medical formulas.
The concept of ideal body weight was originally developed for medical dosing purposes — to help healthcare professionals calculate safe medication doses based on a patient’s estimated lean body mass. Today, ideal weight formulas are widely used in fitness, nutrition and general health planning as practical reference targets.
Our free Ideal Weight Calculator applies four recognised medical formulas simultaneously — Hamwi, Devine, Robinson and Miller — so you receive a range of reference values rather than a single rigid number.
Use our free online Ideal Weight Calculator above to instantly find your ideal weight range.
How to Calculate Ideal Body Weight
Our calculator uses four established medical formulas, each developed independently by different researchers. All four are based on height and gender, using the observation that taller individuals carry proportionally more lean body mass.
1. Hamwi Formula (1964)
Developed by Dr G.J. Hamwi for clinical use in hospitals.
For Men:
Ideal Weight = 48.0 kg + 2.7 kg for every inch over 5 feet (152.4 cm)
For Women:
Ideal Weight = 45.5 kg + 2.2 kg for every inch over 5 feet (152.4 cm)
2. Devine Formula (1974)
Developed by Dr B.J. Devine, widely used in pharmacology for drug dosing.
For Men:
Ideal Weight = 50.0 kg + 2.3 kg for every inch over 5 feet (152.4 cm)
For Women:
Ideal Weight = 45.5 kg + 2.3 kg for every inch over 5 feet (152.4 cm)
3. Robinson Formula (1983)
A revision of the Devine formula with adjusted coefficients based on larger population data.
For Men:
Ideal Weight = 52.0 kg + 1.9 kg for every inch over 5 feet (152.4 cm)
For Women:
Ideal Weight = 49.0 kg + 1.7 kg for every inch over 5 feet (152.4 cm)
4. Miller Formula (1983)
Developed alongside the Robinson formula, often produces slightly higher estimates.
For Men:
Ideal Weight = 56.2 kg + 1.41 kg for every inch over 5 feet (152.4 cm)
For Women:
Ideal Weight = 53.1 kg + 1.36 kg for every inch over 5 feet (152.4 cm)
Example:
A woman who is 168 cm (5 feet 6.9 inches) tall — that is approximately 6.9 inches over 5 feet:
| Formula | Calculation | Ideal Weight |
|---|---|---|
| Hamwi | 45.5 + (2.2 × 6.9) | 60.7 kg |
| Devine | 45.5 + (2.3 × 6.9) | 61.4 kg |
| Robinson | 49.0 + (1.7 × 6.9) | 60.7 kg |
| Miller | 53.1 + (1.36 × 6.9) | 62.5 kg |
The average across all four formulas gives a practical target range of approximately 60–63 kg for this individual.
Ideal Weight Reference Chart by Height
The table below shows approximate ideal weight ranges for adults using the average of the four formulas:
| Height | Ideal Weight — Women | Ideal Weight — Men |
|---|---|---|
| 150 cm (4′ 11″) | 45 – 52 kg | 47 – 55 kg |
| 155 cm (5′ 1″) | 48 – 55 kg | 50 – 58 kg |
| 160 cm (5′ 3″) | 51 – 58 kg | 54 – 62 kg |
| 165 cm (5′ 5″) | 54 – 61 kg | 57 – 65 kg |
| 170 cm (5′ 7″) | 57 – 64 kg | 61 – 69 kg |
| 175 cm (5′ 9″) | 60 – 67 kg | 64 – 72 kg |
| 180 cm (5′ 11″) | 63 – 71 kg | 68 – 76 kg |
| 185 cm (6′ 1″) | 66 – 74 kg | 71 – 80 kg |
| 190 cm (6′ 3″) | 69 – 77 kg | 75 – 84 kg |
These are general reference ranges. Your individual result from the calculator above will be more precise.
Ideal Weight vs. Healthy BMI Weight — What Is the Difference?
Many people confuse ideal body weight with the weight range suggested by a healthy BMI. They are related but not identical:
| Comparison | Ideal Weight Formulas | Healthy BMI Range (18.5–24.9) |
|---|---|---|
| Based on | Height and gender only | Height only (no gender adjustment) |
| Originally developed for | Medical drug dosing | Population-level health screening |
| Muscle mass considered | No | No |
| Gives a single target | Yes — a specific point estimate | No — gives a range of 10–15 kg |
| Best used for | Personal weight goals and medical reference | General health category screening |
For most people, their ideal weight result will fall within or near the healthy BMI range. If the two results differ significantly, it may be worth also checking your body fat percentage using our free Body Fat Calculator for a more complete picture.
Why Knowing Your Ideal Weight Is Useful
Understanding your ideal body weight helps you:
- Set a realistic weight goal — instead of an arbitrary target, you have a medically referenced figure to work toward
- Gauge progress accurately — know when you are within a healthy range versus still working toward it
- Personalise your calorie target — use your ideal weight alongside our Calorie Calculator and TDEE Calculator to calculate the calorie deficit or surplus needed to reach your goal
- Contextualise your BMI — compare your current weight and BMI against your ideal weight range
- Support clinical discussions — ideal body weight is frequently referenced by doctors, nurses and pharmacists when calculating medication doses, anaesthesia requirements and nutritional targets
Limitations of the Ideal Weight Calculator
All four formulas used in our Ideal Weight Calculator were developed decades ago using relatively limited population samples. They share several important limitations:
- Muscle mass is not measured — the formulas assume average body composition. Athletes, bodybuilders and very muscular individuals may weigh significantly more than their calculated ideal weight while maintaining excellent health
- Body frame size is not considered — a person with a naturally larger skeletal frame will carry more healthy weight at the same height than someone with a smaller frame
- Age is not factored in — the formulas do not adjust for the natural changes in body composition that occur with age
- Ethnicity differences — research shows that ideal weight and health risk thresholds can vary between ethnic groups, yet the formulas apply a single universal standard
- Gender is binary in these formulas — the four formulas only distinguish between male and female; they do not account for a wider range of gender identities or hormonal profiles
Use the results as a general reference point rather than a strict target. For personalised guidance, always consult a qualified healthcare professional or registered dietitian.
Who Should Use the Ideal Weight Calculator?
Our free Ideal Weight Calculator is useful for:
- Adults setting a weight loss goal — get a clinically referenced target rather than an arbitrary number
- People monitoring long-term weight management — track progress toward a recognised healthy weight
- Gym beginners and fitness enthusiasts — understand where your weight goal fits relative to clinical benchmarks
- Healthcare students and professionals — quickly reference ideal body weight for clinical or educational purposes
- Anyone curious about their healthy weight range — a simple, instant answer with four perspectives
This calculator is not suitable as a primary guide for:
- Children and teenagers (use BMI-for-age charts designed for growing bodies)
- Pregnant women (weight targets change significantly throughout pregnancy)
- Competitive athletes and bodybuilders (muscle mass makes standard formulas significantly less accurate)
- Individuals with conditions affecting body composition (consult a healthcare professional)
Frequently Asked Questions (FAQ)
Which ideal weight formula is the most accurate?
No single formula is universally the most accurate for all individuals. The Devine formula is the most widely referenced in clinical settings, particularly in pharmacology. However, because each formula was developed from different population samples, looking at the range across all four — as our calculator provides — gives a more balanced and useful reference.
What if my current weight is above my ideal weight?
Being above your calculated ideal weight does not necessarily mean you are unhealthy. Context matters enormously — your body fat percentage, fitness level, muscle mass and overall health markers are all relevant. If you are above the ideal range and also have a high BMI, consider combining our Calorie Calculator with a sustainable exercise plan to move gradually toward your goal.
What if my current weight is already within the ideal range?
This is a positive indicator. Maintain your weight by matching your calorie intake to your TDEE (total daily energy expenditure). Use our free TDEE Calculator to find the right daily calorie target for weight maintenance.
Is ideal weight the same as goal weight?
Not necessarily. Your ideal weight result is a clinically referenced estimate, not a personal target you are obligated to reach. Many people set goal weights above or below their calculated ideal based on personal preferences, athletic goals or medical guidance. The ideal weight range is most useful as a health reference, not a rigid destination.
Why do the four formulas give different results?
Each formula was developed independently by different researchers, using different population samples, at different points in time. The variation between them reflects the reality that no single number perfectly defines a healthy weight for every individual at a given height. The spread across the four formulas — typically 3–8 kg — is itself a useful indicator of the natural range of healthy weights at your height.
Does ideal weight change with age?
The four standard formulas do not adjust for age. However, body composition naturally changes with age — muscle mass tends to decrease and fat mass tends to increase, which can shift what feels and functions as a healthy weight. Older adults should interpret the ideal weight result in discussion with their doctor rather than treating it as an absolute target.
How is ideal weight used in medicine?
In clinical practice, ideal body weight is primarily used to calculate medication doses — particularly for drugs whose distribution is influenced more by lean body mass than total body weight. It is also used in nutrition support planning for hospitalised patients and in anaesthesia calculations. Our free online calculator applies the same formulas used in those clinical contexts.
How to Reach Your Ideal Weight
If you are working toward your ideal weight, a structured approach gives the best long-term results:
- Calculate your calorie target — use our free Calorie Calculator to find the daily calorie intake needed for weight loss, maintenance or gain based on your current weight and activity level
- Track your macronutrients — use the Macro Calculator to ensure you are getting enough protein to preserve muscle while losing fat
- Monitor your BMI — check your BMI Calculator result regularly to track your position across health categories as your weight changes
- Combine diet and exercise — use the Calories Burned Calculator to understand how your workouts contribute to your overall energy balance
- Set a realistic timeline — a safe and sustainable rate of weight loss is 0.25–0.5 kg per week; rushing the process rarely leads to lasting results
- Reassess every 4–6 weeks — as your weight changes, your daily calorie needs change; recalculate regularly using the Calorie Calculator
Final Thoughts
The Ideal Weight Calculator is a practical free online tool that gives you a clinically grounded reference point for your weight goal. By calculating your ideal weight using four established medical formulas simultaneously, it provides a realistic and balanced range rather than a single rigid number.
Use it as part of a broader health picture alongside the full suite of free online health calculators on CalcoraTools — including the BMI calculator, Calorie Calculator, TDEE Calculator, Body Fat Calculator and Macro Calculator — to build a complete, data-driven approach to your health and fitness.
Find your ideal weight now — free, instant and no sign-up required.