I just changed my wife's oil in her 2015 Forester 2.5i. Her low oil light illuminated on her way home from work. Oil level was between add and edge of dipstick after sitting for 2hrs. I'm estimating 1.25qts low. Assuming low to full is 1qt.
Include your cylinders(if not in your signature/profile): 4cyl 2.5i
Odometer: 10,400
miles driven between: 5,000
Quarts added: 1.25
driving style (easy, moderate, aggressive): Easy / All highway
Full engine operating temp (sometimes, usually, almost always): Almost Always