What is an ideal weight calculator?

An ideal weight calculator estimates a healthy weight range for your height, age, and frame. It uses one of several published formulas — there is no single universal "ideal weight" because reasonable healthy ranges span 6-10 kg for any given height.

Use this calculator as a rough target, not an absolute. Body composition (muscle vs fat) matters more than total weight: a 75 kg athletic person can be healthier than a 65 kg sedentary one. For composition, use the Body Fat calculator.

Formulas used

Devine formula (1974) — most common

Men:    50 kg + 2.3 kg per inch over 5 feet
Women:  45.5 kg + 2.3 kg per inch over 5 feet

Robinson formula (1983)

Men:    52 kg + 1.9 kg per inch over 5 feet
Women:  49 kg + 1.7 kg per inch over 5 feet

Miller formula (1983)

Men:    56.2 kg + 1.41 kg per inch over 5 feet
Women:  53.1 kg + 1.36 kg per inch over 5 feet

Hamwi formula (1964)

Men:    48 kg + 2.7 kg per inch over 5 feet
Women:  45.5 kg + 2.2 kg per inch over 5 feet

BMI range method (most defensible)

Compute weight at BMI 18.5 (low healthy) and BMI 24.9 (high healthy):

weight_low  = 18.5 × height² (m²)
weight_high = 24.9 × height² (m²)

Worked example

A man, 175 cm tall (5'9", 9 inches over 5 feet):

Devine:    50 + 2.3 × 9 = 70.7 kg
Robinson:  52 + 1.9 × 9 = 69.1 kg
Miller:    56.2 + 1.41 × 9 = 68.9 kg
Hamwi:     48 + 2.7 × 9 = 72.3 kg

BMI range: 1.75² × 18.5 = 56.6 kg (low)
           1.75² × 24.9 = 76.3 kg (high)

So a 175 cm man's "ideal" by formula sits 69-72 kg, with the healthy BMI range being 56.6-76.3 kg. Most men feel best toward the middle of that BMI range.

For a woman, 162 cm (5'4", 4 inches over 5 feet):

Devine:    45.5 + 2.3 × 4 = 54.7 kg
Robinson:  49 + 1.7 × 4 = 55.8 kg
Miller:    53.1 + 1.36 × 4 = 58.5 kg
Hamwi:     45.5 + 2.2 × 4 = 54.3 kg

BMI range: 1.62² × 18.5 = 48.6 kg
           1.62² × 24.9 = 65.4 kg

Formulas converge around 55-58 kg; healthy BMI range is 48.6-65.4 kg.

Frame size adjustment

Many formulas allow ±10% adjustment based on frame:

• Small frame: subtract 10%
• Medium frame: use formula value
• Large frame: add 10%

Frame size is measured by elbow breadth or wrist circumference:

Elbow breadth (men, medium frame)

Outside that range → small or large frame.

Wrist (men)

• Small: < 16.5 cm
• Medium: 16.5-19 cm
• Large: > 19 cm

Wrist (women)

• Small: < 14 cm
• Medium: 14-16.5 cm
• Large: > 16.5 cm

India-specific considerations

WHO Asia-Pacific BMI thresholds are lower than Western thresholds:

• Underweight: < 18.5
• Normal: 18.5 - 22.9 (Asian) vs 18.5 - 24.9 (WHO global)
• Overweight: 23 - 27.4
• Obese: 27.5+

So an Indian's "ideal" using the BMI method should target 18.5-23 BMI — about 5% lower than the global formulas suggest. For 175 cm man, that's 56.6-70.4 kg instead of 56.6-76.3 kg.

This is because Indians develop metabolic complications (diabetes, heart disease) at lower BMIs than Europeans.

Worked example: Indian-adjusted

Man, 175 cm tall, Indian-adjusted ideal:

Low:  1.75² × 18.5 = 56.6 kg
High: 1.75² × 22.9 = 70.1 kg
Mid:  ~63 kg

Note: this is lower than the Devine formula suggests for the same height. Indian guidelines aim for the leaner end of the global range.

Components and inputs

Sex (biological)

Male / female. Different baseline weights.

Height

In cm or feet/inches. The primary driver.

Age (optional)

For age-adjusted BMI thresholds. Beyond age 65, slightly higher BMI (24-27) is associated with lower mortality than the "young adult" range (paradoxically — see "obesity paradox" in elderly).

Frame size (optional)

Small / medium / large. Adjusts ±10%.

Region preset (optional)

• Global (WHO) — BMI 18.5-24.9
• India / Asia-Pacific — BMI 18.5-22.9

Considerations

• No single ideal weight exists. The "right" weight depends on muscle mass, frame, age, ethnicity, and personal health markers (blood pressure, lipids, glucose).
• Weight alone is misleading. Two people at "ideal weight" can have very different health profiles based on body composition.
• Older adults can be healthier slightly above traditional ideal weight — reduced osteoporosis and sarcopenia risk.
• Athletes routinely exceed "ideal weight" due to muscle mass and are healthier than the formula suggests.
• Cultural body image varies — these formulas are based on epidemiological studies, not aesthetics.

What ideal weight is NOT

• Not a guarantee of health
• Not a goal you must reach
• Not stable across life — natural fluctuation of 5-10 kg with age is normal
• Not based on aesthetics — these are health-oriented numbers
• Not a replacement for medical assessment (blood work, BP, lifestyle factors)

Limitations

• Doesn't account for muscle mass (athletes always exceed "ideal")
• Doesn't account for bone density (high in some ethnicities)
• Less applicable to pregnant women, breastfeeding mothers, people with edema/ascites
• Formulas were derived from primarily Western populations; Asian/African body compositions differ
• Older adults (65+) may benefit from slightly higher weight than "ideal"

Related calculators

• BMI — weight category
• Body Fat — % composition
• BMR — metabolic floor
• Calorie / TDEE — daily needs
• Lean Body Mass — muscle + bone + organ mass

Final note. Ideal weight is a target range, not a fixed number. Pick the BMI-range method for the most defensible answer, adjust 5% lower if you're Indian, and remember that body composition matters more than the scale number. A weight that lets you move freely, sleep well, and shows good lab markers is your real "ideal" — regardless of what the formula says.