This BAI and BMI calculator estimates both your body’s adiposity index and body mass index level and display as well the range category you belong to: underweight, healthy, overweight or obese. There is in depth information about the two formulas employed right after the tool.
How does this BAI and BMI calculator work?
This health tool aims to help you discover two figures that both relate to your body status. One is the traditional BMI range and the other one is the Body Adiposity Index in such a way to let you compare the two results.
The algorithm behind this BAI and BMI calculator uses the equations explained in the next rows, while it takes account of the gender, age range, weight, height and hip circumference:
BAI formula that considers only the hip circumference and height:
BMI formula that requires the height and weight to be given:
Please note that both measurement units English and Metric are supported and that apart from the two health figures, this calculator checks as well the BAI classification (which is gender and age specific) and the BMI range.
BAI classification
Female Body Adiposity Index (BAI) Classification 

Age range 
[BAI_minimum 
BAI_maximum) 
Status 
20  39 
0% 
21% 
Underweight 
20  39 
21% 
33% 
Healthy 
20  39 
33% 
39% 
Overweight 
20  39 
Over 39% 
Obese 

40  59 
0% 
23% 
Underweight 
40  59 
23% 
35 
Healthy 
40  59 
35 
41% 
Overweight 
40  59 
Over 41% 
Obese 

60  79 
0% 
25% 
Underweight 
60  79 
25% 
38% 
Healthy 
60  79 
38% 
43% 
Overweight 
60  79 
Over 43% 
Obese 
Male Body Adiposity Index (BAI) Classification 

Age range 
[BAI_minimum 
BAI_maximum) 
Status 
20  39 
0% 
8% 
Underweight 
20  39 
8% 
21% 
Healthy 
20  39 
21% 
26% 
Overweight 
20  39 
Over 26% 
Obese 

40  59 
0% 
11% 
Underweight 
40  59 
11% 
23 
Healthy 
40  59 
23 
29% 
Overweight 
40  59 
Over 29% 
Obese 

60  79 
0% 
13% 
Underweight 
60  79 
13% 
25% 
Healthy 
60  79 
25% 
31% 
Overweight 
60  79 
Over 31% 
Obese 
BMI ranges
BMI Ranges  no gender specific (in kg/m^{2})  
[BMI_minimum  BMI_maximum)  Status 
0  15  Very severely underweight 
15  16  Severely underweight 
16  18.5  Underweight 
18.5  25  Normal (healthy weight) 
25  30  Overweight 
30  35  Obese Class I (Moderately obese) 
35  40  Obese Class II (Severely obese) 
over 40  Obese Class III (Very severely obese) 
Example of a BAI & BMI calculation
Let’s figure out the two figures for a male aged between 20  39 years having a total weight of 270 lbs, a height of 6 feet and 4 inches and a hip circumference of 35 inches:
■ His Body Adiposity Index (BAI) percentage is 15.15%. Considering this BAI percentage, the gender and the age range his body is Healthy.
■ His Body Mass Index (BMI) is 32.87kg/m^{2}. Based on the BMI ranges his body is considered to be Obese Class I (Moderately obese).
References
1) BMI Classification. (2006) . World Health Organization.
2) Gadzik J. (2006) . Conn Med; 70(2):818.
05 May, 2015