Enter the maximum breadth and length of the head into the calculator to determine the Cephalic Index. This calculator can also evaluate any of the variables given the others are known.

## Cephalic Index Formula

The following formula is used to calculate the Cephalic Index (CI).

CI = (BW / HL) * 100

Variables:

- CI is the Cephalic Index
- BW is the maximum breadth of the head (mm)
- HL is the maximum length of the head (mm)

To calculate the Cephalic Index, divide the maximum breadth of the head by the maximum length of the head. Multiply the result by 100 to get the Cephalic Index.

## What is a Cephalic Index?

The Cephalic Index is a numerical value derived from the measurement of the length and width of the skull. It is used in physical anthropology, archaeology, and forensic science to categorize human skulls into different racial, ethnic, or regional groups. The index is calculated by dividing the maximum width of the head by its maximum length, then multiplying the result by 100. The resulting number is used to classify the skull as either dolichocephalic (long and narrow), mesocephalic (intermediate), or brachycephalic (short and broad).

## How to Calculate Cephalic Index?

The following steps outline how to calculate the Cephalic Index (CI).

- First, determine the maximum breadth of the head (BW) in millimeters (mm).
- Next, determine the maximum length of the head (HL) in millimeters (mm).
- Next, use the formula CI = (BW / HL) * 100 to calculate the Cephalic Index.
- Finally, calculate the Cephalic Index.
- After inserting the values for BW and HL into the formula and calculating the result, check your answer with the calculator above.

**Example Problem:**

Use the following variables as an example problem to test your knowledge.

maximum breadth of the head (BW) = 75 mm

maximum length of the head (HL) = 90 mm