Eighty leaves and up
Guava leaves from Mexico, Psidium guajava, come whole and dried in two sizes. The 8 oz bag holds 80 to 120 leaves, and the bag puts it at 60 to 70 cups. A 2 oz bag sits beside it in our catalog for a smaller first try.
The bag prints a short steep: a tablespoon in a strainer in a mug or teapot, hot water poured over, covered three to five minutes before the strainer comes out. Put the bag's two numbers together and the 8 oz size works out to between one and two leaves for each cup. That gives you a second way to count: about half a dozen leaves for four cups.
In the YERBERO herb shelf, Hoja de guayaba is filed under G in the herbolario A–Z, next to Hierba de San Juan.