How many grafts do I need at 32-years old with a receding hairline? (Photos)

To restore the hairline and the temples, the FUE is the recommended technique. 1800-2000 Grafts are estimated to get maximum density possible in one session. There is no need to use the finasteride and minoxidil at this stage since the hair loss is stable as you mentioned. 

For your age and your hair loss, around 2000 grafts will be enough to get a new hair line with good density

Based on the photos I would estimate between 2000-2500 FUE grafts to fill in the apex (corner areas) of the hair line and frontal forelock. Generally hair loss is progressive, but because your father has a similar hairline may indicate your hair loss will slow down.

As you know, we all have different size heads, thus the number of different hat sizes.  We calculate grafts necessary based on the density and surface area that those grafts will go into.  I agree that a personal consultation is the best way to give you an accurate answer.  I also agree that most hair transplants run around 1500-2500 grafts per procedure.  Find an experienced hair transplant surgeon near you and take the time to get a consult.

The number of grafts you need depends on the thickness of your hairs, the amount of useable donor hair you have, and the hairline you hope to achieve- this all requires a consultation. Generally, most transplants will end up around 1500 - 2500 grafts.

FUE hair transplant can be an option for forehead reduction,  correcting  receding hair line and asymmetry on your frontal hair line/forelock. I advice you have a FUE with 1800-2000 grafts; you would achieve the desired hairline in just one session of dense packing hair transplant. Minoxidil  or finasteride will  not help  you because you dont have a thinning hair but receding hair line   

The number of grafts reflect three factors (1) the design of the hairline, (2) the thickness of each hair shaft from the donor area and (3) a Personalized Master Plan which reflects your age, your examination and your project inheritance for balding based upon family patterns of balding