Calculadora de BAI
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
BAI = (quadril / altura^1,5) − 18
About this calculator
The BAI (Body Adiposity Index) calculator estimates body fat percentage using hip and height measurements. Unlike BMI, which uses weight and height, BAI focuses on hip circumference, making it useful for individuals with high muscle mass. The formula is BAI = (hip in cm / height in meters^1.5) − 18.
To use the calculator, measure your hip at the widest part with a flexible tape and your height. Enter the values and click calculate. The result is an estimated body fat percentage. For example, a person with hip 100 cm and height 1.70 m would have BAI = (100 / (1.70^1.5)) − 18 ≈ 27.3%, indicating moderate fat level.
BAI is useful for assessing metabolic disease risk (e.g., diabetes, hypertension), especially in populations where BMI may be inaccurate (e.g., athletes, elderly). However, it does not replace professional evaluation with methods like bioimpedance or DEXA. Use as a screening tool.
Cautions: BAI was developed for adults aged 18, 65. It may be inaccurate for pregnant women, children, or those with bone deformities. Measure hip without thick clothing, with tape horizontal. Variations up to 2% are normal due to ethnicity and hydration.
Frequently asked questions
Does BAI replace BMI?
No, BAI is an alternative focused on body fat, but both have limitations. BMI is simpler and widely used, while BAI may be better for muscular individuals.
What is the difference between BAI and actual body fat percentage?
BAI is an estimate based on anthropometric measurements. Actual percentage requires exams like DEXA or bioimpedance. BAI serves as an approximation.
Does BAI work for children?
No, BAI was validated only for adults aged 18, 65. For children, use growth charts and age-specific BMI.
Do I need help measuring my hip?
Measure at the widest part of the buttocks, with tape horizontal and snug against the body. Avoid bulky clothing. If possible, ask someone to help.
What does a BAI of 30% mean?
A BAI of 30% indicates high body fat percentage, associated with increased cardiovascular risk. Consult a doctor for a detailed assessment.