What does “ideal body weight” mean?
Historical ideal body weight (IBW) equations estimate reference weights from height and formula coefficients. They were developed for specific applications and do not define one healthy, perfect or recommended weight for every person. Your result needs context such as body composition and medical history.
The four formulas compared
For adult heights at least 5 ft (152.4 cm), this calculator compares Devine, Robinson, Miller and Hamwi estimates. Let i equal height in inches minus 60:
| Formula | Male coefficient | Female coefficient |
|---|---|---|
| Devine | 50 + 2.3 × i | 45.5 + 2.3 × i |
| Robinson | 52 + 1.9 × i | 49 + 1.7 × i |
| Miller | 56.2 + 1.41 × i | 53.1 + 1.36 × i |
| Hamwi | 48 + 2.7 × i | 45.5 + 2.2 × i |
Every result in the table is in kilograms. The US setting accepts height in inches; results are currently displayed in kilograms, not pounds.
Adult BMI reference weight range
The calculator also shows an illustrative weight interval based on BMI 18.5 to 24.9, using weight (kg) = BMI × height (m)². For a height of 170 cm, the corresponding interval is approximately 53.5 to 72.0 kg. This population-based screening range is not an individual treatment target.
Height-based reference chart
The following figures are approximate adult BMI 18.5–24.9 references, not ideal-weight prescriptions:
| Height | Indicative reference (kg) |
|---|---|
| 160 cm | 47.4–63.7 |
| 165 cm | 50.4–67.8 |
| 170 cm | 53.5–72.0 |
| 175 cm | 56.7–76.3 |
| 180 cm | 59.9–80.7 |
| 185 cm | 63.3–85.2 |
How to interpret the estimates safely
The historical formulas are not supported below 152.4 cm in this tool. Adult BMI thresholds are not intended for children or teenagers, pregnancy and certain health conditions. A higher weight can reflect muscle or other factors rather than excess fat. For accurate personal advice, consult a qualified health professional.
Background reading: CDC adult BMI reference categories.
Frequently asked questions
What is my ideal weight at 170 cm?
The adult BMI 18.5–24.9 screening interval for 170 cm is approximately 53.5–72.0 kg. It is not a personal goal.
Do I need to enter weight?
No. This calculator estimates historical weight references from your height and selected equation coefficients.
Can I input my height in feet and inches?
The US input accepts total height in inches; multiply feet by 12 and add extra inches before entering it.
Are results available in pounds?
The current calculator shows reference weights in kilograms, even if you entered height in inches.
Which is the correct weight formula?
No single historical IBW formula describes everyone. The equations use different constants and may disagree.
Why does it not accept heights below 5 feet?
The historical formulas on this page use a five-foot baseline, so the calculator limits their application accordingly.
Is the BMI range a weight-loss target?
No. It is a broad adult screening reference, not a personalized instruction to gain or lose weight.
Is this suitable for children?
No. Growth assessments for children and teenagers use age-specific methods.