Ideal Body Weight Calculator

Calculate your ideal body weight for your height using various formulas with the IBW calculator.

Gender:
Gender:

Ideal Weight:

 

Ideal Weight using Various Formulas

Robinson Formula[1] (1983): 
Miller Formula[2] (1983): 
Devine Formula[3] (1974): 
Hamwi Formula[4] (1964): 
Range for Healthy BMI[5]: 


How to Calculate Your Ideal Body Weight

Ideal body weight (IBW) is an estimate of what an individual’s healthy weight should be based on certain parameters, most notably height and gender. This value is the optimal weight for a given height that corresponds to a favorable fitness and nutrition status.

Maintaining an ideal body weight is associated with a decreased risk of chronic health issues and early mortality. On the other hand, obesity is associated with an increased prevalence of cardiovascular disease, hypertension, diabetes, and even certain forms of cancer.

Calculating what your IBW should be is one way to ensure you are maintaining a healthy weight.

Ideal Body Weight Formulas

Several different formulas have been developed over the years to estimate ideal body weight. Interestingly, these equations were first introduced to estimate drug metabolism and clearance from the body as research has found that these factors relate more to ideal body weight than actual total body weight.[6]

Most of the ideal body weight formulas were derived using population data and weight trends. These ideal body weight equations all share a general agreement among the different height-weight tables from which they were based.

Since these formulas all give similar results, any one of these equations may be used to estimate IBW.

The Devine Formula

The first IBW equation was introduced by Ben J. Devine in 1974 to allow estimation of drug clearances in obese patients.[7] This is still one of the most commonly used formulas to calculate ideal body weight in clinical practice today.

The Devine Formula uses height only to determine ideal body weight. This equation was initially based on estimates of ideal body weight and not population studies.

Men:
Ideal Body Weight [kg] = 50 + (2.3 × (height [in] – 60))

Women:
Ideal Body Weight [kg] = 45.5 + (2.3 × (height [in] – 60))

So, in this formula, a 5’5″ female would have an IBW of:

45.5 + (2.3 × 5) = 57 kg

To convert this to pounds, multiply by 2.2.

57 kg × 2.2 lbs/kg = 125.4 pounds

Hamwi Formula

The Hamwi formula is very similar to the Devine formula. However, the Hamwi equation also uses body frame in predicting ideal body weight. The base equation assumes a medium frame. This can then be adjusted either by increasing by 10% for those with a large body frame or decreasing by 10% for those with a small body frame.

Men:
Ideal Body Weight [kg] = 48 kg + (2.7 × (height [in] – 60))

Women:
Ideal Body Weight [kg] = 45.5 kg + (2.2 × (height [in] – 60))

Sometimes this common equation is also seen written using imperial units:

Men:
Ideal Body Weight [lbs] = 106 + (6 × (height [in] – 60))

Women:
Ideal Body Weight [lbs] = 100 + (5 × (height [in] – 60))

Once you calculate ideal body weight using the above equation, you can then adjust this based on your frame size. This may seem subjective, however one way to determine frame size is by using your wrist measurement.

Using a tape measure, you simply measure the circumference of your wrist. If the wrist measurement is seven inches, the body frame is considered medium. Above seven inches is considered a large body frame, while measurements below seven inches correspond to a small body frame.

In addition, for individuals that are less than 60 inches in height (5 feet), you need to subtract 5 pounds for each inch below 60.

Small frame (- 10%), Large frame (+ 10%)

For heights less than 60″, subtract 5 lbs. for each inch below 60

For example, the above 5’5″ female with a medium frame would have an ideal body weight of 125 pounds.

100 + (5 × 5)) = 125

However, for this same woman with a large frame, her IBW would be:

125 × 0.1 = 12.5 lbs
125 + 12.5 = 137.5 lbs

And if this woman had a small frame, her IBW would be:

125 × 0.1 = 12.5 lbs
125 – 12.5 = 112.5 lbs

Robinson Formula

The Robinson formula was developed on the basis of the 1959 Metropolitan Life Insurance Company height-weight tables. This equation was created to better assess ideal body weight for drug dosing.

Men:
Ideal Body Weight [kg] = 52 + (1.9 × (height [in] – 60))

Women:
Ideal Body Weight [kg] = 49 + (1.7 × (height [in] – 60))

Using this formula, a 5’5″ female would have an IBW of:

49 kg + (1.7 × 5) = 57.5 kg

To convert this to pounds, multiply by 2.2.

57.5 kg × 2.2 lbs/kg = 126.5 pounds

Miller Formula

Similar to the Robinson equation, the Miller equation was formulated on the basis of 1983 Metropolitan Life Insurance Company height-weight tables.

Men:
Ideal Body Weight [kg] = 56.2 + (1.41 × (height [in] – 60))

Women:
Ideal Body Weight [kg] = 53.1 + (1.36 × (height [in] – 60))

The values are slightly different as this formula was based on more recent population data.

Using this formula, a 5’5″ female would have an IBW of:

53.1 + (1.36 × 5) = 60 kg

To convert this to pounds, multiply by 2.2.

60 kg × 2.2 lbs/kg = 132 pounds

Ideal Body Weight: A Range Rather Than One Number

One of the downfalls of calculating ideal body weight is that it only gives one number based on an individual’s height and gender. These formulas do not take into account other factors, such as lean body mass, genetic makeup, physical activity, or age.

And, unlike BMI, there is no set “healthy range” formally associated with ideal body weight. Plus, using a different equation will give you a slightly different value for ideal body weight.

Studies have even found that in practice, it might be more useful to use BMI ranges instead of IBW formulas for men and women.[8] However, you can use a BMI chart in combination with ideal body weight calculations to determine your ideal body weight range.

Healthy Weight Range

For most people, a healthy weight range will fall within the healthy BMI range of 18.5 – 25. Of course, individual circumstances may mean that some people with higher muscle mass may fall outside of these numbers. However, in general, this is a good range to follow.

BMI Chart

Body mass index weight categories defined by the CDC
Weight Category BMI
Underweight <18.5
Healthy Weight 18.5 – 24.9
Overweight 25 – 29.9
Class 1 Obesity 30 – <35
Class 2 Obesity 35 – <40
Class 3 Obesity >40

How Much Should You Weigh

When determining your ideal body weight, there are a number of variables you should take into account. The equations for ideal body weight take into account gender and height, which do play one key role in what would be considered a healthy body weight.

However, other factors, such as your body type, frame size, health conditions, muscle mass, and physical activity also are important determining factors in your ideal body weight.

The National Institute of Health has also developed a chart that combines BMI and body weight ranges based on height to aid in determining your ideal, healthy body weight.[9]

Healthy weight and BMI ranges based on height according to the National Institute of Health
Height Healthy Weight
(Ideal Body Weight)
Overweight Obesity Severe Obesity
BMI: 19 – 24.9 BMI: 25 – 29 BMI: 30 – 39 BMI: 40 – 54
60″ 97-123 lbs 128-148 lbs 153-199 lbs 204-276 lbs
61″ 100-127 lbs 132-153 lbs 158-206 lbs 211-285 lbs
62″ 104-131 lbs 136-158 lbs 164-213 lbs 218-295 lbs
63″ 107-135 lbs 141-163 lbs 169-220 lbs 225-304 lbs
64″ 110-140 lbs 145-169 lbs 174-227 lbs 232-314 lbs
65″ 114-144 lbs 150-174 lbs 180-234 lbs 240-324 lbs
66″ 118-148 lbs 155-179 lbs 186-241 lbs 247-334 lbs
67″ 121-153 lbs 159-185 lbs 191-249 lbs 255-334 lbs
68″ 125-158 lbs 164-190 lbs 197-256 lbs 262-354 lbs
69″ 128-162 lbs 169-196 lbs 203-263 lbs 270-365 lbs
70″ 132-167 lbs 174-202 lbs 209-271 lbs 278-376 lbs
71″ 136-172 lbs 179-208 lbs 215-279 lbs 286-386 lbs
72″ 140-177 lbs 184-213 lbs 221-287 lbs 284-397 lbs
73″ 144-182 lbs 189-219 lbs 227-295 lbs 302-408 lbs
74″ 148-186 lbs 194-225 lbs 233-303 lbs 311-420 lbs
75″ 152-192 lbs 200-232 lbs 240-311 lbs 319-431 lbs
76″ 156-197 lbs 205-238 lbs 246-320 lbs 328-443 lbs

These formulas provide a good starting point to estimate your ideal body weight to ensure that you fall within a healthy range for your height.

This is just one more tool when putting together a fitness and nutrition program to meet your health goals, and should be combined with other measures such as lean body mass and body fat percentage when computing your own healthy ideal body weight.

References

  1. J D Robinson, S M Lupkiewicz, L Palenik, L M Lopez, M Ariet, Determination of ideal body weight for drug dosage calculations, The American Journal of Hospital Pharmacy, 1983, 40(6), 1016-9. https://pubmed.ncbi.nlm.nih.gov/6869387/
  2. Nutrition House, Miller Formula, https://www.nutritionhouse.com/Library/WellnessItem.aspx?ID=66016
  3. Manjunath P Pai, Frank P Paloucek, The Origin of the “Ideal” Body Weight Equations, Annals of Pharmacotherapy, 2000, 34(9), 1066-1069. https://journals.sagepub.com/doi/10.1345/aph.19381
  4. Courtney M Peterson, Diana M Thomas, George L Blackburn, and Steven B Heymsfield, Universal equation for estimating ideal body weight and body weight at any BMI, The American Journal of Clinical Nutrition, 2016, 103(5), 1197-1203. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4841935/
  5. Centers for Disease Control and Prevention, Assessing Your Weight, https://www.cdc.gov/healthyweight/assessing/index.html
  6. Pai, M. P., & Paloucek, F. P., The origin of the 'ideal' body weight equations, The Annals of pharmacotherapy, 2000, 34(9), 1066–1069. https://pubmed.ncbi.nlm.nih.gov/10981254/
  7. McCarron, M. M., & Devine, B. J., Clinical Pharmacy: Case Studies: Case Number 25 Gentamicin Therapy, Drug Intelligence & Clinical Pharmacy, 1974, 8(11), 650–655. https://journals.sagepub.com/doi/10.1177/106002807400801104
  8. Shah, B., Sucher, K., & Hollenbeck, C. B., Comparison of ideal body weight equations and published height‐weight tables with body mass index tables for healthy adults in the United States, Nutrition in clinical practice, 2006, 21(3), 312-319. https://aspenjournals.onlinelibrary.wiley.com/doi/abs/10.1177/0115426506021003312
  9. Expert Panel on the Identification, Treatment of Overweight, Obesity in Adults (US), National Heart, Lung, Blood Institute, ... & Kidney Diseases (US), Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults: the evidence report (No. 98), National Institutes of Health, National Heart, Lung, and Blood Institute, 1998, https://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmi_tbl.pdf