verb (used with or without object), bifurcated, bifurcating. 1. to divide or fork into two branches. adjective. 2. divided into two branches.
Advertisement. By the Numbers. According to the National Sleep Foundation, newborns should sleep 12 to 18 hours out of every 24 (every new parent hopes), with a gradual reduction to 12 to 14 hours for toddlers ages 1 to 3; 11 to 13 hours for preschoolers 3 to 5; and (yes!) 10 to 11 hours for schoolchildren ages 5 to 10.
Toddlers (1 to 2 years): 11 to 14 hours of sleep. Preschoolers (3 to 5 years): 10 to 13 hours of sleep. School-aged children (6 to 13 years): 9 to 11 hours of sleep. Teenagers (14 to 17 years): 8 to 10 hours of sleep. Young adults (18 to 25 years): 7 to 9 hours of sleep. Adults (26 to 64 years): 7 to 9 hours of sleep. Older adults (65 years or older): 7 to 8 hours of sleep. Although most men and women need about seven to eight hours of sleep per night, their sleep patterns are generally different.