The formulas to calculate body fat percentage are:
For Females:
\[ D = 1.09949 - (0.00099 \times (\text{Triceps} + \text{Thigh} + \text{Suprailiac})) + (0.0000023 \times (\text{Triceps} + \text{Thigh} + \text{Suprailiac})^2) - (0.0001392 \times \text{Age}) \]
For Males:
\[ D = 1.10938 - (0.0008267 \times (\text{Thigh} + \text{Chest} + \text{Abdomen})) + (0.0000016 \times (\text{Thigh} + \text{Chest} + \text{Abdomen})^2) - (0.000257 \times \text{Age}) \]
Body density is then transformed into body fat percentage using the SIRI formula:
\[ \text{Body Fat Percentage} = \frac{495}{D} - 450 \]
Body Fat Caliper is the process of estimating a person’s body fat based on three different skinfold measurements obtained from calipers.
Example 1 (Female):
Step 1: Calculate body density (D):
\[ D = 1.09949 - (0.00099 \times (20 + 30 + 15)) + (0.0000023 \times (20 + 30 + 15)^2) - (0.0001392 \times 25) \approx 1.045 \]
Step 2: Calculate body fat percentage:
\[ \text{Body Fat Percentage} = \frac{495}{1.045} - 450 \approx 23.35\% \]
Example 2 (Male):
Step 1: Calculate body density (D):
\[ D = 1.10938 - (0.0008267 \times (25 + 20 + 30)) + (0.0000016 \times (25 + 20 + 30)^2) - (0.000257 \times 30) \approx 1.070 \]
Step 2: Calculate body fat percentage:
\[ \text{Body Fat Percentage} = \frac{495}{1.070} - 450 \approx 12.62\% \]