Ideal weight calculator: a healthy range for your height
The ideal weight calculator leads with a reference range: 18.5 × height² to 24.9 × height², with height in metres and weight in kilograms. At 1.70 m, the range is 53.5–72.0 kg. Devine, Robinson, Miller, Hamwi and Lorentz are historical conventions, not personal targets. BMI alone says nothing about an individual’s health.
Values recalculate as you type. No measurements are sent or stored: the math runs in your browser.
This calculator is general information, not medical advice. BMI and the ideal-weight formulas are statistical estimates: they describe populations, not you. They cannot diagnose anything. If your weight, your health or a result you have seen here worries you, talk it over with a healthcare professional, who can weigh your body composition, your history and your circumstances. Do not change your food, your medication or your activity because of a number on this page.
If weight is a source of distress for you, seeing an "ideal weight" can do harm. The healthy range is wide on purpose, and a number on its own does not measure your health.
How the calculation works
Range (kg) = 18.5 × h² to 24.9 × h²; h = height in metres.
The upper endpoint uses 24.9 to match WHO’s printed label. The classification interval extends to 25 exclusive; that distinction is 0.3 kg at 1.70 m. Endpoints round only at the end to one decimal; 71.961 kg displays as 72.0 kg.
Range source: WHO.
Limits of the estimate
BMI cannot distinguish muscle from fat or show where fat is carried. Short stature, older age, high muscularity, fluid retention and pregnancy can make the result especially misleading.
BMI helps describe populations and support an initial assessment, but cannot determine an individual’s health, body composition or risk.
These bands and formulas do not apply to people under 19, people who are pregnant or breastfeeding, people with a lot of muscle mass, people retaining fluid, or people with amputations or certain medical conditions. In those cases the reference has to come from a healthcare professional.
Sources: WHO, IMSS 2018, SEEDO 2016 and PRONAM 2025.
There is no single ideal weight. Peterson and colleagues (2016) found that almost all historical equations underestimated weight at short heights and overestimated it at tall heights. Disagreement is not a reason to pursue the smaller number.
Healthy-weight reference range by height
| Height (cm) | BMI 18.5 endpoint (kg) | BMI 24.9 endpoint (kg) |
|---|---|---|
| 150 | 41.6 | 56.0 |
| 155 | 44.4 | 59.8 |
| 160 | 47.4 | 63.7 |
| 165 | 50.4 | 67.8 |
| 170 | 53.5 | 72.0 |
| 175 | 56.7 | 76.3 |
| 180 | 59.9 | 80.7 |
| 185 | 63.3 | 85.2 |
| 190 | 66.8 | 89.9 |
| 195 | 70.3 | 94.7 |
| 200 | 74.0 | 99.6 |
Historical formulas alongside the range
H is height in inches (cm ÷ 2.54); C is height in centimetres. All expressions below return kg. Hamwi is calculated in pounds first, then converted with 1 lb = 0.45359237 kg; no body-frame adjustment is applied.
| Formula | Male: output (kg) | Female: output (kg) |
|---|---|---|
| Devine (1974) | 50 + 2.3 × (H − 60) | 45.5 + 2.3 × (H − 60) |
| Robinson (1983) | 52 + 1.9 × (H − 60) | 49 + 1.7 × (H − 60) |
| Miller (1983), Peterson 2016 | 56.2 + 1.41 × (H − 60) | 53.1 + 1.36 × (H − 60) |
| Hamwi (1964) | [106 + 6 × (H − 60)] × 0.45359237 | [100 + 5 × (H − 60)] × 0.45359237 |
| Lorentz | C − 100 − (C − 150) / 4 | C − 100 − (C − 150) / 2.5 |
Devine began as a gentamicin dosing rule; Robinson and Miller fitted Metropolitan Life Insurance height-weight tables. Historical use in dosing does not make these values a health plan or authorize calculating medication doses here. The reviewed sources do not explain how Hamwi was developed.
Devine’s 1974 original is not openly available: coefficients are quoted from the secondary reproductions by Peterson et al., AJCN 2016 and Ideal body weight: a commentary, 2021. Miller follows Peterson (56.2/1.41 and 53.1/1.36); the 2021 commentary prints 55.7/1.39 and 53/1.33. The 1983 original was unavailable, so that discrepancy remains unresolved. Robinson uses the agreed 52/1.9 and 49/1.7 variant. Lorentz comes from the 2016 SEGG geriatric consensus as an assessment convention, not an appearance goal.
BMI for women and men
The BMI formula is the same for women and men. The sex variable only identifies the short-stature thresholds in Mexico’s norm; it does not change weight divided by height squared. BMI alone says nothing about an individual’s health. These categories are not used here during pregnancy or breastfeeding.
BMI for children and by age
No adult category is returned below age 19. WHO growth references for ages 5–19 interpret BMI by age and sex. Children under five need growth indicators such as weight for height. A clinician must interpret those references; a fixed adult table cannot replace them.
From age 60, the adult reading remains a reference with an explicit warning. Mexico’s NOM-008 gives overweight at 28–31.9 kg/m² and obesity at ≥32 kg/m². The IMSS downloadable table uses 25 and 30 kg/m² without naming an age group. Spain’s SEGG geriatric consensus gives normal weight 22–26.9, overweight 27–29.9 and obesity ≥30 kg/m². These different references should be discussed with a professional.
Mexico’s short-stature thresholds
For ages 20–59, NOM-008-SSA3-2017 defines short stature as under 160 cm for men or under 150 cm for women. It gives overweight at 23–24.9 kg/m² and obesity at ≥25 kg/m² for that group. The calculator flags this difference when applicable without replacing clinical assessment or applying these labels to muscularity.
Frequently asked questions
What is my ideal weight for my height?
There is no single ideal weight for a height. This calculator shows the reference interval associated with BMI 18.5–24.9: at 1.70 m, that is 53.5–72.0 kg. It is a broad statistical reference, not a personal goal. Body composition, age and clinical circumstances matter, and a professional can help interpret them.
How is the healthy-weight range calculated?
Height in metres squared is multiplied by 18.5 for the lower endpoint and by 24.9 for the upper endpoint. At 1.70 m, the unrounded results are 53.465 and 71.961 kg. This page displays 53.5–72.0 kg. The upper endpoint follows WHO’s printed 24.9 label rather than the exclusive threshold of 25.
What is the difference between Devine and Robinson?
Devine starts with 50 kg for men or 45.5 kg for women, adding 2.3 kg per inch above five feet. Robinson starts with 52 and 49 kg, adding 1.9 and 1.7 kg respectively. These historical conventions relate to dosing and insurance tables; neither determines what an individual should weigh.
Why do ideal-weight formulas disagree?
The formulas use different samples, periods and assumptions, and several developed in medication dosing. Peterson and colleagues found that almost all underestimated weight at short heights and overestimated it at tall heights. Miller also has conflicting coefficients in published reproductions. That is why a BMI range leads here and each convention’s source is disclosed.
Does ideal weight change with age?
The BMI-range formula uses height alone, but interpreting the range requires age context. Before nineteen, growth references are needed. In older adults, Mexico’s NOM-008 and Spain’s SEGG publish different thresholds. This calculator does not add an arbitrary number of kilograms per birthday or select a personal goal from those competing references.
What if the result worries me?
A number on this page does not measure your health or worth and does not require you to change your body. If weight or eating causes distress, you can leave the calculator and seek support from a healthcare professional. Do not change eating, medication or activity based only on these results.
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