Jacob was about 1 year old when he dropped down to 1 nap per day. You'll know your baby is ready when he/she starts to skip the afternoon nap. My son would always take his a.m. nap, but then he started to protest the 2nd. Every other day or so he would take the 2nd nap, but it would be short. So, I pushed his a.m. nap to noon and he slept until 3 every day.