PERCOCET 2.5 mg/325 mg. The usual adult dosage is one or 2 tablets every 6 hours as needed for pain. The total daily dose of acetaminophen should not exceed 4 grams. PERCOCET 5 mg/325 mg; PERCOCET 7.5 mg/325 mg; PERCOCET 10 mg/325 mg. The usual adult dosage is one tablet every 6 hours as needed for pain. The total daily dose of acetaminophen should not exceed 4 grams.