How many grafts would I need for a hair transplant for female forehead reduction? (Photo)

Photos cannot determine if you would be a good candidate for surgery.  You need an examination and the doctor needs to understand your goals and expectations.
You need to have good communication with your doctor to understand what your end result will look like. 
Someone with your goal may be perfectly happy with 1500 grafts, while others may not be happy even with over 3000 grafts.  You also have to realize one surgery may not be enough.  To add to the confusion, straight black hair on fair skin results in a thinner appearing outcome then someone with curly blond hair on fair skin.   I hope you can appreciate there are many factors to your end result than just a "number" of grafts.Cost also depends on the doctor and the type of the procedure.

To accomplish the results that you are looking for you can either have a hairline lowering procedure that Brings the hairline forward, or  you could have hair grafting to the area. If grafting is performed you would likely need around 1200 to 1500 grass. If you have very fine hair you may need more. An accurate assessment of what would be required Can be made during an in person consultation. In addition platelet rich plasma injections can help to supplement the results.
Best regards, Dr. WEISS

Hairline lowering by hair transplantation to this level will require around 1400 to 1500 grafts. But it will be better to meet a surgeon in your area and then discuss in detail

There are two ways to lower an overly high female hairline- one is the hairline lowering /forehead reduction surgery, the other is with hair grafting.  With grafting, given the rather significant amount of lowering and rounding out you desire (and with which I agree), I'd anticipate 1900 to 2200 grafts.  Then there is the small but definite chance that 10 plus months later you will want some further filling in of the central frontal hairline to achieve good density-  for especially in this area it is most challenging to achieve excellent density.

As low as you outlined your desired hairline, you would be looking at a good number of grafts.Do your research and submit your photos to some of the top hair restoration doctors in the U.S who are known for their female hair restorations.

Your design of the hairline is right on. It would take between 1600-2000 grafts, less with a coarser hair and more with a fine hair.  My wife had it done with fine, blonde hair and it took 2000 grafts.