The two-nap to one-nap transition is one of those parenting milestones nobody warns you about properly. My daughter did it at 13 months. My son held onto two naps until he was 18 months, at which point he just decided he was done and that was that. Most toddlers transition from two naps to one somewhere between 12 and 18 months. The average is around 14 to 15 months. Signs your toddler might be ready: they start refusing the second nap entirely, or they take both naps but then will not sleep at bedtime until very late. The transition usually takes 2 to 6 weeks and it is not linear. Some days they will need two naps, some days one, some days neither because they have decided sleep is for the weak. The one-nap schedule typically works best with the nap happening around 11:30am to 12:30pm. Start by pushing the morning nap 15 to 30 minutes later every few days until you land on a lunchtime nap. Expect overtired meltdowns during the transition. This is normal. Early bedtimes help enormously: 6 to 6:30pm during the transition period is not unusual and it genuinely helps. Do not drop the nap entirely during the transition day. If you are out and they fall asleep in the buggy or car on the way home, that counts. Do not panic. Just adjust bedtime accordingly. Most toddlers are reliably on one nap within 4 to 6 weeks of starting the transition.