What is an ideal weight calculator?
An ideal weight calculator estimates a healthy body weight for your height and gender. Doctors and dietitians have used ideal body weight (IBW) formulas for decades – to dose medicines, to set ventilator tidal volume and to give patients a realistic target. This free online ideal weight calculator applies the four best-known formulas – Robinson, Miller, Devine and Hamwi – and adds the healthy weight range from BMI, so you get a single sensible target band in kg and pounds instead of one rigid number.
It answers the questions people most often type into search: "what should my ideal weight be?", "what is a healthy weight for my height?" and "what is my ideal weight in kg?". It works as an ideal weight calculator for men and an ideal weight calculator for women, in centimetres or in feet and inches.
How to use the ideal weight calculator
- Select your gender – the formulas give women a slightly lower base weight.
- Enter your height in cm, or in feet and inches.
- Optionally enter your current weight in kg to see your BMI and how far you are from the healthy range.
The result shows the lowest and highest of the four ideal body weight formulas, their average, and the BMI-based healthy weight range for your height.
Ideal body weight formulas
All four formulas start with a base weight at 5 feet (152.4 cm) and add a fixed amount for every inch above 5 feet:
| Formula | Men | Women |
|---|---|---|
| Robinson (1983) | 52 kg + 1.9 kg per inch over 5 ft | 49 kg + 1.7 kg per inch |
| Miller (1983) | 56.2 kg + 1.41 kg per inch | 53.1 kg + 1.36 kg per inch |
| Devine (1974) | 50 kg + 2.3 kg per inch | 45.5 kg + 2.3 kg per inch |
| Hamwi (1964) | 48 kg + 2.7 kg per inch | 45.5 kg + 2.2 kg per inch |
The healthy BMI range is worked out from the BMI formula rearranged for weight:
Healthy weight = BMI × height(m)² , for BMI 18.5 to 24.9
The Devine formula is the one most used in hospitals (for example as the ideal body weight in tidal volume calculations for ventilated patients). Robinson and Miller were later refinements that give lower values for tall people.
Worked example: how to calculate ideal weight for men
A man is 175 cm tall. 175 ÷ 2.54 = 68.9 inches, which is 8.9 inches over 5 feet. Robinson: 52 + 1.9 × 8.9 = 68.9 kg. Miller: 56.2 + 1.41 × 8.9 = 68.7 kg. Devine: 50 + 2.3 × 8.9 = 70.5 kg. Hamwi: 48 + 2.7 × 8.9 = 72.0 kg. The healthy BMI range is 18.5 × 1.75² = 56.7 kg to 24.9 × 1.75² = 76.3 kg. So a sensible ideal weight in kg for this man is about 69–72 kg, and anything from 57 to 76 kg is a healthy weight.
Worked example: how to calculate ideal weight for women
A woman is 5 ft 4 in (162.6 cm), 4 inches over 5 feet. Robinson: 49 + 6.8 = 55.8 kg. Miller: 53.1 + 5.4 = 58.5 kg. Devine: 45.5 + 9.2 = 54.7 kg. Hamwi: 45.5 + 8.8 = 54.3 kg. Her ideal weight is about 54–59 kg, with a healthy BMI range of 48.9–65.8 kg.
Ideal weight chart by height (kg)
This ideal height and weight chart uses the Devine formula and the BMI 18.5–24.9 range:
| Height | Ideal weight – male | Ideal weight – female | Healthy BMI range |
|---|---|---|---|
| 5 ft 0 in (152 cm) | 50.0 kg | 45.5 kg | 43.0 – 57.8 kg |
| 5 ft 2 in (157 cm) | 54.6 kg | 50.1 kg | 45.9 – 61.8 kg |
| 5 ft 4 in (163 cm) | 59.2 kg | 54.7 kg | 48.9 – 65.8 kg |
| 5 ft 5 in (165 cm) | 61.5 kg | 57.0 kg | 50.4 – 67.9 kg |
| 5 ft 6 in (168 cm) | 63.8 kg | 59.3 kg | 52.0 – 70.0 kg |
| 5 ft 7 in (170 cm) | 66.1 kg | 61.6 kg | 53.6 – 72.1 kg |
| 5 ft 8 in (173 cm) | 68.4 kg | 63.9 kg | 55.2 – 74.3 kg |
| 5 ft 10 in (178 cm) | 73.0 kg | 68.5 kg | 58.5 – 78.7 kg |
| 6 ft 0 in (183 cm) | 77.6 kg | 73.1 kg | 61.9 – 83.3 kg |
So the ideal weight for a 5'5" male is roughly 61–63 kg, for a 5'7" male about 65–67 kg, for a 5'8" male about 66–70 kg, for a 5'10" male in kg about 70–75 kg, and for a 6 feet male about 73–80 kg. The ideal weight for a 5 feet female is about 45–53 kg, for a 5'4" female in kg about 54–59 kg and for a 5'5" female about 55–60 kg.
Ideal weight calculator for India
For Indian adults, the Ministry of Health and many Indian doctors use Asian BMI cut-offs: 18.5–22.9 is normal and 23 or more is overweight, because South Asians develop diabetes and heart disease at lower BMI. The calculator therefore also shows an Indian BMI range. An ideal weight calculator for Indian male or Indian female users should aim for the lower half of the standard healthy range. A quick Indian rule of thumb – height in cm minus 100 for men, minus 105 for women – gives similar answers (75 kg for a 175 cm man, 57 kg for a 162 cm woman), but the formulas above are more consistent.
Does age, frame size or muscle change your ideal weight?
The IBW formulas ignore age, frame size and muscle. In practice:
- Frame size: people with a large bone structure can add about 10% to the result, small-framed people subtract about 10% (Hamwi's original advice).
- Muscle: athletes and people who lift weights often sit above their "ideal" weight while being lean. Check your body fat percentage instead of weight alone.
- Age: older adults (65+) are often healthier at the upper end of the BMI range, since a little extra weight protects against frailty.
- Children: an ideal weight calculator for kids or babies must use age-and-sex growth charts (WHO or IAP charts in India), not these adult formulas.
How to reach your goal weight
If you are above your target, a deficit of about 500 kcal a day loses roughly 0.5 kg a week. Work out your needs with the calorie calculator, keep protein high, and track your BMI every few weeks.
Units, age, frame size and body fat: what to enter
Ideal weight calculator in kg for male and female
Choose male or female and the ideal weight calculator shows the result in kg with pounds (lbs) alongside.
Ideal weight calculator for India: male and female, in kg
For India, the results include the Indian BMI range, which uses Asian cut-offs. An Indian male or female should read that row for a target weight in kg.
Height, age and gender
People often want an ideal weight calculator according to height, age and gender. The IBW formulas use only height and gender; age changes how you read the result (older adults can sit higher in the range) rather than the formula itself.
Ideal weight calculator in cm or feet
Enter your height in cm, or switch to feet and inches. The result updates instantly.
Ideal weight calculator with body fat percentage
If you know your body fat percentage, work it out a different way: target weight = lean mass ÷ (1 − target body fat %). For example, 60 kg of lean mass at a 15% target gives 70.6 kg. For people who lift weights and carry extra muscle, this is the best ideal weight calculator method.
Ideal weight calculator with frame size
To check your frame size, wrap your thumb and middle finger around your wrist: if they overlap you have a small frame (subtract 10%), if they just touch a medium frame, and if they do not meet a large frame (add 10%). The adjustment makes the result fairer for people who are genuinely large boned.
Ideal weight calculator for kids and babies
A pediatric ideal weight calculator must use WHO or IAP growth charts, because every baby and child grows at a different rate. This adult tool is not suitable for kids.
Ideal body weight calculator formula for medical use
Hospitals use the Devine formula. In an ideal body weight calculator for ventilator settings, tidal volume is 6–8 ml/kg of IBW.
Goal weight calculator: how long will it take?
Divide the kg you need to lose by 0.5 kg per week. Losing 10 kg takes about 20 weeks at a safe pace.
What is ideal weight for 5'4 female in kg and other heights?
The chart above answers it: about 54–59 kg for 5'4", and the range row gives the healthy BMI band for any height.
Is this the most accurate ideal weight calculator?
No single formula is perfect, so the most accurate approach is to combine them. This free ideal weight calculator online shows all four formulas plus the BMI range for any adult. To calculate ideal weight according to height by hand, use the Devine formula above.
What should my ideal weight be? Calculator answers in three steps
There is no single answer to what is my ideal weight, so this ideal weight calculator gives a range. To answer what should my weight be, the calculator works in three steps:
- Enter your height and sex to get the Devine, Robinson, Miller and Hamwi results.
- Check the healthy BMI weight range for your height (18.5–24.9, or 18.5–22.9 on the Asian scale).
- Pick a target inside that range that suits your frame and muscle; the formula results usually fall near its middle.
Ideal body weight quick calculation
For a quick calculation without a calculator, use the Devine rule: men start at 50 kg and women at 45.5 kg for 5 feet, then add 2.3 kg for every inch above 5 feet. A 5'8" man: 50 + 8 × 2.3 = 68.4 kg. A 5'4" woman: 45.5 + 4 × 2.3 = 54.7 kg.
Ideal weight calculator by ethnicity: Asia, Europe and NZ
Health risks start at a lower BMI in Asian people, so the healthy range shifts down. In India and Singapore, a BMI of 23 or more is treated as higher risk, so an ideal weight calculator for Singapore or India should use the Asian range shown in the results. In Japan, the ideal weight calculator should use the Japanese standard weight: Japan uses a "standard weight" of height in metres squared × 22, so a 1.70 m person's standard weight is about 63.6 kg. In Europe, the US and New Zealand, the WHO range of 18.5–24.9 is used for most adults, although studies in NZ suggest many Pacific and Māori adults carry more muscle at the same BMI. As an obesity check, if the result shows a target far below your current weight and your BMI is 30 or more (25 or more on the Indian scale), talk to a doctor about a safe plan.
Ideal weight chart for girls and ideal weight in kg for kids
Children do not have an "ideal" weight from a formula, so an ideal weight calculator in kg for kids would mislead; doctors compare them with growth charts instead. WHO median weights for girls, a useful reference point:
| Age | 1 year | 2 years | 3 years | 4 years | 5 years |
|---|---|---|---|---|---|
| Median weight (girls) | 8.9 kg | 11.5 kg | 13.9 kg | 16.1 kg | 18.2 kg |
WHO medians for boys are slightly higher, by about 0.1–0.7 kg at these ages. A healthy child can be well above or below the median; what matters is steady growth along their own curve, so ask your paediatrician to plot it.
Ideal weight calculator for a dog
Dogs are judged by body condition score (BCS), not a height formula. On the 9-point scale, 4–5 is ideal: you can feel the ribs easily, and there is a visible waist from above. A rough rule used by vets: each point above 5 means about 10% extra weight, so a 22 kg dog with a BCS of 7 has an ideal weight of about 22 ÷ 1.2 ≈ 18 kg. Ask your vet to confirm.
Frequently asked questions
How is ideal weight calculated?
Ideal weight formulas start from a base weight at 5 feet and add a set number of kilograms for each inch of height above 5 feet. This calculator shows the Robinson, Miller, Devine and Hamwi results and the healthy BMI range for your height.
What is the ideal weight for a 5 feet 5 inch female in kg?
About 55–60 kg by the IBW formulas, with a healthy BMI range of roughly 50–68 kg.
What is the ideal weight for a 5 feet 8 inch male in kg?
About 66–70 kg by the four formulas; the healthy BMI range is about 55–74 kg.
What is the ideal weight for a 6 feet male?
Around 73–80 kg by the IBW formulas, with a healthy BMI range of about 62–83 kg.
Which ideal body weight formula is most accurate?
None is perfect. Devine is the medical standard, Robinson and Miller give lower values for tall people. Using the range of all four plus the BMI range gives the most reasonable target.
Does the ideal weight calculator consider age?
The formulas do not use age. Older adults can reasonably aim for the upper part of the healthy BMI range. Children need growth charts instead.
Can I use it for Indian men and women?
Yes. The calculator also shows the Indian BMI range of 18.5–22.9, which suits South Asian adults better than the international 24.9 limit.
What should my ideal weight be?
A weight that puts your BMI between 18.5 and 24.9 (18.5–22.9 for Asians). The formula results in this calculator usually fall near the middle of that range.
What is the quickest way to calculate ideal body weight?
Devine rule: 50 kg for men or 45.5 kg for women at 5 feet, plus 2.3 kg for every inch above 5 feet.
Last updated 2026-09-18