# What is my ideal body weight range?

Estimates ideal body weight for a height and sex with the Devine, Robinson, Miller, and Hamwi equations, and the healthy weight range for BMI 18.5 to 25.

- Page: https://www.acalculator.org/health/ideal-weight-calculator
- JSON spec: https://www.acalculator.org/health/ideal-weight-calculator.json
- Version: b7ec40c18674

## Default answer

Example with the default inputs (Height 5 ft 10 in, Sex Male): The Devine formula gives an ideal weight of 160.9 lb; the healthy BMI range for this height is 128.9 lb to 174.2 lb.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| height | Height | Your height without shoes. |
| devine | Devine formula | Ideal body weight by the Devine formula: 50 kg + 2.3 kg per inch over 5 ft (men); 45.5 kg + 2.3 kg per inch (women). |
| robinson | Robinson formula | Ideal body weight by the Robinson formula: 52 kg + 1.9 kg per inch over 5 ft (men); 49 kg + 1.7 kg per inch (women). |
| miller | Miller formula | Ideal body weight by the Miller formula: 56.2 kg + 1.41 kg per inch over 5 ft (men); 53.1 kg + 1.36 kg per inch (women). |
| hamwi | Hamwi formula | Ideal body weight by the Hamwi formula: 106 lb + 6 lb per inch over 5 ft (men); 100 lb + 5 lb per inch (women). |
| bmiLow | Healthy weight from | The lowest weight in the healthy BMI range for this height: 18.5 × height². |
| bmiHigh | Healthy weight up to | The weight at which BMI reaches 25 for this height, 25 × height²; the healthy range ends just below it. |
| sex | Sex | Sex at birth. Each formula has one line for men and one for women. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| height | Height | Your height without shoes. |
| devine | Devine formula | Ideal body weight by the Devine formula: 50 kg + 2.3 kg per inch over 5 ft (men); 45.5 kg + 2.3 kg per inch (women). |
| robinson | Robinson formula | Ideal body weight by the Robinson formula: 52 kg + 1.9 kg per inch over 5 ft (men); 49 kg + 1.7 kg per inch (women). |
| miller | Miller formula | Ideal body weight by the Miller formula: 56.2 kg + 1.41 kg per inch over 5 ft (men); 53.1 kg + 1.36 kg per inch (women). |
| hamwi | Hamwi formula | Ideal body weight by the Hamwi formula: 106 lb + 6 lb per inch over 5 ft (men); 100 lb + 5 lb per inch (women). |
| healthyMin | Healthy weight from | The lowest weight in the healthy BMI range for this height: 18.5 × height². |
| healthyMax | Healthy weight up to | The weight at which BMI reaches 25 for this height, 25 × height²; the healthy range ends just below it. |

## Method

Ideal weight = base + slope × (height in inches − 60): Devine 50 + 2.3 (men), 45.5 + 2.3 (women) kg; Robinson 52 + 1.9, 49 + 1.7 kg; Miller 56.2 + 1.41, 53.1 + 1.36 kg; Hamwi 106 + 6, 100 + 5 lb. Healthy range = 18.5 × height² to 25 × height² (kg, m).

## Assumptions

- The four equations were made for adults 5 ft (60 in) and taller. Below 5 ft, the same straight lines are continued down to 4 ft.
- Hamwi’s pounds are converted with 1 lb = 0.45359237 kg exactly; 1 in = 0.0254 m exactly.
- The healthy weight range is the CDC adult BMI range, 18.5 up to (just under) 25.
- Ideal body weight equations were made for drug dosing and height-weight tables. They do not account for muscle, frame, or age, and this is not medical advice.

## Worked examples

1. sex = male, height = 1.778 gives devine = 73, robinson = 71, miller = 70.3, hamwi = 75.296333, bmiLow = 58.483754, bmiHigh = 79.0321. Source: Peterson and others (2016), Am J Clin Nutr, Table 3 equations; hand calculation in content.mdx: 50 + 2.3 × 10 = 73 kg; 52 + 1.9 × 10 = 71 kg; 56.2 + 1.41 × 10 = 70.3 kg; 106 + 6 × 10 = 166 lb = 75.30 kg; 18.5 and 25 × 1.778² (CDC BMI range).
2. sex = female, height = 1.6256 gives devine = 54.7, robinson = 55.8, miller = 58.54, hamwi = 54.431084. Source: Peterson and others (2016), Table 3; hand calculation in content.mdx: 45.5 + 2.3 × 4 = 54.7 kg; 49 + 1.7 × 4 = 55.8 kg; 53.1 + 1.36 × 4 = 58.54 kg; 100 + 5 × 4 = 120 lb = 54.43 kg.
3. sex = male, devine = 73 gives height = 1.778, robinson = 71. Source: hand calculation in content.mdx: the Devine line solved for height, 60 + (73 − 50) ÷ 2.3 = 70 in = 1.778 m.
4. sex = female, hamwi = 58.967008 gives height = 1.6764, devine = 59.3. Source: hand calculation in content.mdx: the Hamwi line for women solved for height, 60 + (130 − 100) ÷ 5 = 66 in = 1.6764 m; Devine at 66 in: 45.5 + 2.3 × 6 = 59.3 kg.

## FAQ

### How do I calculate my ideal weight?

Take your height in inches over 5 feet and use a formula. The Devine formula is 50 kg + 2.3 kg per inch for men and 45.5 kg + 2.3 kg per inch for women. A man 5 ft 10 in tall is 10 inches over 5 feet, so his Devine ideal weight is 50 + 2.3 × 10 = 73 kg (161 lb).

### Which ideal weight formula should I use?

The Devine formula (1974) is the one most used in medicine, mainly for drug doses. Robinson and Miller (both 1983) refitted the same idea to insurance height-weight tables, and Hamwi (1964) is an older rule in pounds. Peterson and others (2016) found that the formulas agree with the same idea as BMI only roughly, so the healthy BMI range is a better guide to a healthy weight.

### What is a healthy weight for my height?

The weight that gives a BMI from 18.5 to just under 25 at your height (CDC adult categories): 18.5 × height² to 25 × height², with height in metres and weight in kilograms. At 5 ft 10 in (1.778 m), that is about 58.5 to 79.0 kg, or 129 to 174 lb.

### Why do the formulas give different answers?

They were fitted to different height-weight data at different times. They also grow at different rates with height: Devine adds 2.3 kg per inch for men, Miller only 1.41 kg. The gap is small near 5 ft 6 in and grows for very short or very tall people.

### Can I use this if I am shorter than 5 feet?

The formulas were written for heights of 5 feet and more. The calculator continues the same straight lines down to 4 feet, so results below 5 feet are extrapolated and less reliable.

### Does ideal weight account for muscle or body frame?

No. The formulas use only height and sex. A muscular person can weigh more than their ideal body weight and still be healthy. Body fat percentage or waist size says more about body composition.

## Sources

- Peterson CM, Thomas DM, Blackburn GL, Heymsfield SB. Universal equation for estimating ideal body weight and body weight at any BMI. American Journal of Clinical Nutrition 2016;103:1197–1203, Table 3. doi:10.3945/ajcn.115.121178
- Pai MP, Paloucek FP. The origin of the "ideal" body weight equations. Annals of Pharmacotherapy 2000;34:1066–1069. doi:10.1345/aph.19381
- Devine BJ. Gentamicin therapy. Drug Intelligence and Clinical Pharmacy 1974;8:650–655.
- Robinson JD, Lupkiewicz SM, Palenik L, Lopez LM, Ariet M. Determination of ideal body weight for drug dosage calculations. American Journal of Hospital Pharmacy 1983;40:1016–1019.
- Miller DR, Carlson JD, Lloyd BJ, Day BJ. Determining ideal body weight (and mass). American Journal of Hospital Pharmacy 1983;40:1622–1625.
- Hamwi GJ. Therapy: changing dietary concepts. New York: American Diabetes Association, 1964.
- Centers for Disease Control and Prevention, Adult BMI Categories. https://www.cdc.gov/bmi/adult-calculator/bmi-categories.html
- NIST SP 811 (2008), Appendix B: 1 lb = 0.45359237 kg and 1 in = 0.0254 m exactly.