Calculate Ideal Body Weight Under 5 Feet
Estimate ideal body weight for shorter adult heights using classic clinical formulas and compare the result with a BMI-based healthy weight range.
Your results will appear here
Enter a height under 5 feet, choose sex and formula, then click calculate.
Formula Comparison Chart
The chart compares four commonly cited ideal body weight formulas for the height you enter. This makes it easier to see how much estimates can vary.
Expert Guide to Calculating Ideal Body Weight Under 5 Feet
Calculating ideal body weight under 5 feet is a little different from using a standard height and weight chart for average adult heights. Many classic medical formulas were originally designed around a baseline of 5 feet and then adjusted by adding or subtracting a fixed number of kilograms for every inch above or below that mark. That means if someone is shorter than 5 feet tall, the formulas can still be used, but they need to be applied carefully. This page is built to help you estimate ideal body weight for shorter adults using well known clinical methods while also comparing those estimates with the healthy BMI range recognized by major public health organizations.
It is important to understand what ideal body weight actually means. In medicine, the phrase usually refers to a calculated reference weight, not a perfect or universal target. Health professionals may use it when estimating medication dosing, nutritional needs, fluid requirements, and ventilator settings. It is not the same thing as your healthiest possible weight, your athletic weight, or your preferred weight. For adults under 5 feet, ideal body weight formulas should be viewed as a starting point rather than a final judgment.
Why adults under 5 feet need special attention
Many online calculators are built with average adult heights in mind and may not clearly explain how the formulas work for people under 60 inches tall. In practice, the same equations can usually be extended below 5 feet by subtracting the relevant amount per inch. For example, the Devine formula uses 50 kg for men and 45.5 kg for women at exactly 5 feet. If the person is 4 feet 10 inches, that is 2 inches below the baseline, so the formula subtracts 2 times the formula adjustment. Other formulas, including Robinson, Miller, and Hamwi, use different baselines and adjustment values, which is why calculators often produce different results for the same person.
This is especially relevant for adults with naturally short stature, certain genetic syndromes, endocrine conditions, spinal curvature, limb differences, or demographic and ethnic backgrounds where shorter height is common. In these situations, formula output may still be useful, but interpretation should be individualized. If a doctor, dietitian, or pharmacist is using ideal body weight for a clinical purpose, they may rely on one specific formula for consistency rather than because it is universally superior.
The most commonly used formulas
Here are four traditional ideal body weight equations often used in adult settings. These formulas are usually expressed using a 5 foot baseline:
- Devine: Men 50 kg at 5 feet, women 45.5 kg at 5 feet, adjusted by 2.3 kg per inch.
- Robinson: Men 52 kg at 5 feet, women 49 kg at 5 feet, adjusted by 1.9 kg per inch for men and 1.7 kg per inch for women.
- Miller: Men 56.2 kg at 5 feet, women 53.1 kg at 5 feet, adjusted by 1.41 kg per inch for men and 1.36 kg per inch for women.
- Hamwi: Men 48 kg at 5 feet, women 45.5 kg at 5 feet, adjusted by 2.7 kg per inch for men and 2.2 kg per inch for women.
For a height under 5 feet, you subtract rather than add. If someone is 4 feet 9 inches tall, they are 3 inches below 5 feet. The Devine estimate for a woman would be 45.5 minus 2.3 times 3, which equals 38.6 kg. The equivalent calculation in pounds is about 85.1 lb. This does not mean every woman at 4 feet 9 inches should weigh exactly 85.1 pounds. It means that 85.1 pounds is the formula based reference point generated by that method.
BMI and healthy weight range for shorter heights
Because ideal body weight formulas can vary, it is often helpful to compare them with a BMI-based healthy range. The Centers for Disease Control and Prevention defines healthy adult BMI as 18.5 to 24.9. For shorter adults, this range can be translated into a weight interval. Unlike the classic formulas, BMI produces a range rather than a single target. This is often more practical in real life because normal body weight is not a single number.
The healthy BMI range is particularly useful for adults under 5 feet because it naturally scales to height. However, BMI is also imperfect. It does not directly measure body fat, bone density, or muscle mass. A petite person with a lot of muscle may have a BMI that looks high relative to their body composition, while another person may have a normal BMI but carry more body fat than expected.
| Height | BMI 18.5 Weight | BMI 24.9 Weight | Healthy Weight Range |
|---|---|---|---|
| 4 ft 6 in | 77.6 lb | 104.5 lb | 77.6 to 104.5 lb |
| 4 ft 7 in | 80.5 lb | 108.3 lb | 80.5 to 108.3 lb |
| 4 ft 8 in | 83.4 lb | 112.3 lb | 83.4 to 112.3 lb |
| 4 ft 9 in | 86.4 lb | 116.4 lb | 86.4 to 116.4 lb |
| 4 ft 10 in | 89.4 lb | 120.5 lb | 89.4 to 120.5 lb |
| 4 ft 11 in | 92.5 lb | 124.8 lb | 92.5 to 124.8 lb |
The table above uses the standard adult BMI thresholds of 18.5 and 24.9. It shows why a single ideal body weight value should not be interpreted too rigidly. A formula output for a 4 foot 10 adult may fall near the lower end, middle, or upper end of the healthy BMI range depending on which equation is used and whether the person is male or female.
How to calculate ideal body weight under 5 feet step by step
- Measure height accurately in feet and inches.
- Convert height to total inches. For example, 4 ft 10 in equals 58 inches.
- Find how many inches below 5 feet the person is. Since 5 feet equals 60 inches, 58 inches is 2 inches below baseline.
- Select a formula such as Devine, Robinson, Miller, or Hamwi.
- Subtract the formula adjustment per inch below 5 feet from the baseline weight at 5 feet.
- Convert kilograms to pounds if needed by multiplying kilograms by 2.20462.
- Compare the result with the BMI healthy weight range for that height.
That final comparison is where context matters. If a person’s formula derived ideal weight is below the lower end of the healthy BMI range, that does not automatically make the formula wrong. It may simply reflect the fact that each method was developed for different practical purposes. Many clinicians therefore use ideal body weight and BMI together instead of choosing only one.
Comparison example with real calculated values
To show how much variation exists, the table below compares formula outputs for a woman who is 4 feet 10 inches tall and a man of the same height. These are direct calculations from the formulas listed earlier.
| Formula | Female 4 ft 10 in | Male 4 ft 10 in | Notes |
|---|---|---|---|
| Devine | 40.9 kg / 90.2 lb | 45.4 kg / 100.1 lb | Subtracts 2.3 kg for each inch below 5 feet. |
| Robinson | 45.6 kg / 100.5 lb | 48.2 kg / 106.3 lb | Produces somewhat higher values for shorter women than Devine. |
| Miller | 50.4 kg / 111.0 lb | 53.4 kg / 117.8 lb | Often yields the highest estimate among these examples. |
| Hamwi | 41.1 kg / 90.6 lb | 42.6 kg / 94.0 lb | May produce a lower male estimate than Devine at shorter heights. |
Notice the spread. For a 4 foot 10 woman, one formula gives around 90 lb while another gives about 111 lb. That is a large gap. This is exactly why calculators should show more than one method and why no single formula should be treated as a perfect standard for health or appearance.
When these calculations are most useful
- Medication planning: Some dosing protocols use ideal body weight or adjusted body weight.
- Clinical nutrition: Dietitians may use reference weights to estimate calorie and protein needs.
- Hospital care: Respiratory and critical care teams may use ideal body weight for specific technical settings.
- General screening: It can help a shorter adult understand whether their weight is broadly below, within, or above a conventional reference zone.
Important limitations for adults under 5 feet
There are several reasons ideal body weight formulas can be less reliable for very short adults. First, the formulas were created from historical data and practical conventions, not from direct measurements of healthy body composition in every subgroup. Second, people with short stature may have unique body proportions, which means a fixed adjustment per inch may oversimplify reality. Third, age matters. An older adult with reduced muscle mass may have a different healthiest weight range than a younger adult with more lean mass. Fourth, the formulas do not account for ethnicity, body frame, or trained muscle mass.
For these reasons, the best approach is usually to combine multiple indicators:
- Ideal body weight formula output
- BMI and healthy BMI range
- Waist circumference if appropriate
- Trend over time rather than one reading
- Clinical context such as medications, chronic disease, appetite, and physical function
What public health sources say
Major public health authorities generally emphasize healthy weight ranges and BMI categories rather than a single ideal number. The CDC provides adult BMI category definitions, while the National Institute of Diabetes and Digestive and Kidney Diseases offers BMI resources and discussion of healthy weight. MedlinePlus, from the U.S. National Library of Medicine, also offers general background on weight and BMI. These sources are useful for understanding the broader health context even though they may not focus specifically on under 5 foot ideal body weight formulas.
Authoritative references:
- CDC Adult BMI information
- NIDDK BMI and healthy weight resources
- MedlinePlus overview of body mass index
Practical interpretation tips
If your calculated ideal body weight is lower than your current weight, it does not automatically mean you should try to lose weight. A healthy next step is to compare your current measurements with the BMI healthy range, your waist measurement if relevant, and your doctor’s assessment of blood pressure, glucose, cholesterol, and physical function. If your calculated ideal body weight is higher than your current weight, that also does not automatically mean you are underweight. You may naturally be smaller framed, or another formula may fit you better.
In short, calculating ideal body weight under 5 feet is useful when you treat it as a reference, not a verdict. The best method is to calculate several formula estimates, compare them with a healthy BMI range, and then interpret the numbers in a broader clinical and personal context. That is exactly why this calculator displays both a selected formula result and a comparison chart. It helps you see the full picture instead of relying on one isolated number.