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- Ideal weight formulas estimate a weight from height and sex. This calculator uses the Devine, Robinson, Miller and Hamwi formulas.
- It also shows the weight range that matches a BMI of 18.5 to 24.9 for your height, which is wider and more widely used.
- Every formula adds a set amount of weight for each inch of height over 5 feet (60 inches).
- They ignore age, frame size and muscle, so treat the result as a rough guide. This page is general information, not medical advice.
How to use the ideal weight calculator
Choose your sex
The formulas use different starting weights for men and women.
Choose units and enter your height
Use centimeters, or feet and inches.
Read the range
The main result shows the lowest and highest answer of the four formulas for your height.
Compare the formulas
Each formula is listed on its own, next to the healthy BMI range.
The four ideal weight formulas
Formulas (height over 5 feet)
Devine (1974): men 50 kg, women 45.5 kg, plus 2.3 kg per inch
Robinson (1983): men 52 kg + 1.9 kg per inch, women 49 kg + 1.7 kg per inch
Miller (1983): men 56.2 kg + 1.41 kg per inch, women 53.1 kg + 1.36 kg per inch
Hamwi (1964): men 106 lb + 6 lb per inch, women 100 lb + 5 lb per inch
Every formula counts only the inches above 5 feet, which is 60 inches or 152.4 cm.
The Devine formula was originally created to help estimate medicine doses and is now one of the most quoted ideal weight formulas. The others were written later and give slightly different answers, so the calculator shows all four. If you are shorter than 5 feet, the formulas extend the same pattern downward, which is less reliable.
Worked examples
Example 1: a man 170 cm tall
170 cm is about 66.9 inches, which is 6.93 inches over 5 feet.
The formulas agree closely, while the BMI range is much wider.
Example 2: a woman 165 cm tall
165 cm is about 64.96 inches, which is 4.96 inches over 5 feet.
Again the BMI range allows for a lot more variety than the single-number formulas.
Example 3: US units
A man is 5 ft 10 in tall, which is 10 inches over 5 feet.
The calculator shows pounds when you choose US units.
Ideal weight versus healthy weight
The four formulas give a single number near the middle of the healthy range, which is why their results sit close together. The BMI range is much wider. For a 170 cm adult it runs from about 53.5 kg to 72.0 kg. That wider window reflects real differences in bone structure, muscle and body type. Two people of the same height and sex can both be healthy at weights many kilograms apart.
Useful conversions
Quick conversions
Handy when you move between metric and US units.
The formulas start counting at 5 feet, which is 152.4 cm.
Where an ideal weight calculator helps
Health check-ins
Get a rough weight range to talk through with a doctor.
Fitness goals
Compare a goal weight with the formulas and the healthy BMI range.
Comparing formulas
See how the four classic formulas differ for your height.
Forms and plans
Fill in a reference weight with a sensible range.
Check your BMI with the BMI calculator, estimate daily energy needs with the BMR calculator, or find daily protein with the protein intake calculator. This page is general information and not medical advice. Please talk to a doctor or other health professional about a healthy weight for you.
Ideal weight calculator FAQ
What is ideal body weight?
It is an estimated weight for a person of a given height and sex, found with simple formulas. It is a rough guide, not a target that suits everybody.
Which formula is the most accurate?
None is clearly the best. They all use height and sex only and give similar answers, which is why the calculator shows all four and the healthy BMI range.
Why do the formulas give different results?
Each formula was built from different data and uses its own starting weight and weight per inch, so the answers differ by a few kilograms.
Is the BMI range better than the formulas?
The BMI range is wider and widely used by health organizations. It allows for different body types, so it is often the more useful of the two.
Does ideal weight depend on age or muscle?
Not in these formulas. They ignore age, frame size, muscle and body fat, so a muscular person may weigh more than the result and still be healthy.
Should I aim for my ideal weight?
Use it only as a rough reference. Talk to a doctor before setting a weight goal, especially if you have a health condition or are under 18.