At 21 months of age, 88% of children are taking 1 nap and 12% are taking 2 naps/day.

The average total duration of naps is 2.4 hours and the range is 1-4 hours. 97% of children nap between 1.5-3.5 hours.

Nap duration is largely under genetic control: some infants will usually take long or very long naps and others will usually take brief or very brief naps. Adjust the bedtime to keep your baby's sleep tank full between 4-5 pm. Don't compare babies.

Marc

Healthy Sleep Habits, Happy Child

Weissbluth Method Infant Nap App.