Depending on the size motor if it's a 4 cylinder 5 quarts of oil, 6 cylinder usually between 5-6 quarts and a 8 cylinder 6 quarts.
Check your manual that should be in the glove box. Since there are different cars and trucks that have 4 6 8 cylinder motors . On average its 4 to 6 quartz.
In focus c. Max 1.8 cc
It should be on a user manual, if not, the oil dipstick will tell you.