Ideal Weight Calculator

HealthLast updated: August 17, 2026

Ideal weight is the body weight considered healthy for your height and sex. The medical literature uses more than one formula for it: Devine (1974, the standard for drug dosing calculations), Robinson (1983), Miller (1983), and Hamwi (1964). For the same height each can differ by a few kilograms, which is why it is more accurate to think of a range than of a single number.

This calculator shows the result of all four classic formulas together with their average, and it also computes the weight band that corresponds to the World Health Organization's healthy BMI range (18.5 – 24.9). That way you see both the target weight the traditional formulas point to and the broader scientifically accepted healthy range at a glance.

cm
Enter your height in centimeters (for example, 170 for 1.70 m).

Current Ideal Weight References

There is no single official "rate" for ideal weight; the medical literature uses four classic formulas alongside the World Health Organization's BMI range. This calculator reports the references below.

Devine formula
1974
The most widely used reference in drug dosing calculations; the de facto standard of clinical practice
Robinson formula
1983
A revised version of the Devine formula; it usually returns a result a few kilograms lower
Miller formula
1983
Uses coefficients that rise more slowly as height increases
Hamwi formula
1964
The oldest of the four methods; it generally gives the highest result
WHO healthy BMI range
18.5 – 24.9
Multiplied by height squared to convert it into a weight band; for people shorter than 152.4 cm it is more reliable than the formulas
Spread between the formulas
±3–5 kg
For the same height the four formulas differ by a few kilograms, so read the result as a range rather than a single number

The formulas have not changed since they were published; the WHO range has been in force since 2000Kaynak: Devine (1974), Hamwi (1964), Robinson (1983), Miller (1983), and the World Health Organization BMI classification

Formula

Devine:   Male 50.0 + 2.3 × in | Female 45.5 + 2.3 × in
Robinson: Male 52.0 + 1.9 × in | Female 49.0 + 1.7 × in
Miller:   Male 56.2 + 1.41 × in | Female 53.1 + 1.36 × in
Hamwi:    Male 48.0 + 2.7 × in | Female 45.5 + 2.2 × in
WHO range = from 18.5 × Height²(m) to 24.9 × Height²(m)

The 'in' in these formulas is the part of the height above 5 feet (152.4 cm), expressed in inches: (Height − 152.4) / 2.54. The formulas were developed for heights above 152.4 cm; for shorter people the WHO BMI range is the more reliable reference.

How to Calculate

  1. Enter your height in centimeters.
  2. Choose your sex — the coefficients of all four formulas depend on it.
  3. Read each formula's result and their average in the results section.
  4. Treat the range on the WHO row as the lower and upper bound of a healthy weight.

Worked Examples

Man 180 cm tall

For a man 180 cm tall, Devine gives 75.0 kg, Robinson 72.6 kg, Miller 71.5 kg, and Hamwi 77.3 kg; the four formulas average 74.1 kg. The WHO healthy weight range is 59.9 – 80.7 kg.

Average of the four formulas: 74.1 kg · Devine formula: 75.0 kg · Robinson formula: 72.6 kg

Woman 165 cm tall

For a woman 165 cm tall, Devine gives 56.9 kg, Robinson 57.4 kg, Miller 59.8 kg, and Hamwi 56.4 kg, for an average of 57.7 kg. According to the WHO, the healthy range is 50.4 – 67.8 kg.

Average of the four formulas: 57.7 kg · Devine formula: 56.9 kg · Robinson formula: 57.4 kg

Man 172 cm tall

For a man 172 cm tall the formulas agree closely: Devine 67.7, Robinson 66.7, Miller 67.1, and Hamwi 68.8 kg, averaging 67.6 kg. The WHO range is 54.7 – 73.7 kg.

Average of the four formulas: 67.6 kg · Devine formula: 67.7 kg · Robinson formula: 66.7 kg

Frequently Asked Questions

Which ideal weight formula is the most accurate?
There is no single 'most accurate' formula; all of them are statistical estimates based on height. The Devine formula is the best known because it is the standard for calculating drug doses in medicine. In practice, a balanced approach is to treat the average of the four formulas as a target and the WHO BMI range as the healthy band.
Why do the formulas give different results?
Each was developed in a different year from different population data, and each uses a different coefficient for every inch of height above 152.4 cm. The gap is usually around 3-6 kg, which shows that ideal weight is a range rather than an exact number.
Does ideal weight account for muscle mass?
No. The formulas use only height and sex; they ignore muscle-to-fat distribution, frame size, and age. Athletes with high muscle mass can be perfectly healthy above the formula result. If you are curious about body composition, look at the body fat percentage calculator as well.
I am shorter than 152 cm; are the results valid?
The four classic formulas were developed for heights above 5 feet (152.4 cm); below that they only return their base value and become unreliable. In that case the weight band derived from the WHO BMI range is the better reference.
What should I do to reach my ideal weight?
A safe rate of change is 0.25 – 0.5 kg per week, which takes a daily deficit or surplus of roughly 250-500 kcal. You can set your daily target with the calorie needs calculator and follow it with regular weigh-ins. For large weight goals, working with a dietitian is recommended.
Does age affect ideal weight?
These formulas do not include age; however, as you get older muscle mass falls and fat percentage rises, so body composition at the same weight changes. Studies suggest that slightly higher BMI values (23-28) are associated with better health outcomes above the age of 65; in older age the target weight should be set with a doctor.