Baking salmon in the oven takes between 15 to 20 minutes depending on how well done you want the salmon to be cooked.
I like to cook my salmon in the oven for 20 minutes which is when the salmon is baked and cooked enough for me.
I cook my salmon in the oven at 350 F for the 20 minutes and before putting the salmon in the oven I like to brush it with some Avocado oil and put black pepper on it.
Also the baked Salmon will be done and fully cooked when it flakes easily with a fork which means it's ready to eat or serve.