: 3 bundles are the "magic number" for standard fullness.

: Curly or deep wave hair appears fuller, so you might need fewer bundles compared to straight hair. 3. Match Texture and Color Weaves 101: Everything You Need to Know About ... - Unruly

: 2 to 3 bundles are usually enough for a full look.

The number of bundles depends on the length of the hair and the size of your head. On average, a woman's head circumference is 22.5 inches.