One full day if you drive it clockwise and skip Killarney town. Two if you add the Skellig Ring, which is the better half.
Ireland
Is 2 days enough for the Ring of Kerry?
Accepted answer
Do the Cliffs of Moher need a booked slot in July?
Accepted answer
Pre-book the car park slot — it's the parking that sells out, not the cliffs. Before 10:00 or after 17:00 and the coaches are gone.
Card or cash in rural Ireland?
Accepted answer
Card everywhere, including the smallest pub. Keep €20 for a market stall or a paper parking disc and you'll come home with most of it.
Kissing the Blarney Stone — actually worth the queue?
Accepted answer
With kids that age, yes — go at opening. The gardens are the part the adults end up liking.