The number of packs of Fusion I-Tips you will need to purchase will depend on several factors, such as the desired length, thickness, and volume you want to achieve, as well as the density and length of your natural hair. As a general rule of thumb, for a full head installation, we recommend 4 to 6 packs of Fusion I-Tips for hair that is of average thickness and length. However, if you have thinner or shorter hair, you may require fewer packs, while thicker or longer hair may require more packs. We always recommend consulting with a professional stylist to determine the appropriate amount of Fusion I-Tips for your specific hair needs.