A 15 month old needs 11 to 14 hours of total sleep per day, including naps. Most children this age get around 11 hours at night and make up the rest with one or two daytime naps. That range comes from both the American Academy of Pediatrics and the National Heart, Lung, and Blood Institute, and it applies to all children between 1 and 2 years old.
How Those Hours Break Down
At 15 months, the split between nighttime sleep and naps depends largely on whether your child is still taking two naps or has transitioned to one. A child on two naps typically sleeps about 10.5 to 11 hours overnight, with two shorter naps during the day adding up to 2 to 3 hours. A child on one nap often sleeps 11 to 11.5 hours at night and takes a single longer nap of about 2 to 2.5 hours around lunchtime.
Most children land somewhere in the 12 to 13 hour range when you add it all up. Hitting the lower end of the 11 to 14 hour window is fine as long as your child seems rested and alert during the day.
The Two-to-One Nap Transition
By 15 months, many children have dropped their second nap in favor of one longer midday nap. This transition is one of the biggest schedule shifts in the first two years, and it rarely happens cleanly. Some toddlers bounce back and forth between one and two naps for weeks before settling into a single-nap routine.
During this transition, expect some overtiredness. The single nap often starts short, around 60 to 90 minutes, and it can take a week or more before it stretches to the 2 to 3 hours your child needs. On days when that one nap is especially short, an earlier bedtime (by 30 to 45 minutes) can help make up the difference.
If your child is still happily taking two naps and sleeping well at night, there’s no reason to force the switch. The transition typically happens somewhere between 13 and 18 months, and timing varies widely.
Wake Windows to Watch For
Wake windows, the stretches of awake time between sleep periods, are a useful tool for getting nap timing right. For a 15 month old still on two naps, aim for 3 to 4 hours of awake time between sleeps. For a child on one nap, that window stretches to 4 to 6 hours.
If your child is on one nap and waking at 7 AM, a nap starting around noon works well. The goal is to avoid pushing your toddler so far past their window that they become wired and have trouble falling asleep, but also not putting them down so early that they only sleep briefly.
Why Sleep Falls Apart Around This Age
Fifteen months is a common age for sleep disruptions, and there are several reasons hitting at once. Walking (or learning to walk) is the big one. Toddlers who are mastering a new motor skill often practice it in their cribs, pulling to stand and then struggling to settle back down. Language development is also accelerating, and the mental processing involved can make sleep lighter and more fragmented.
Teething is often blamed for night waking at this age, and it’s true that first molars typically come in between 13 and 19 months. But teething pain generally doesn’t wake a child from deep sleep. If your toddler is suddenly waking every hour through the night, the cause is more likely developmental than dental. Teething may make falling asleep harder initially, but the repeated overnight waking that parents describe usually has more to do with the nap transition, new physical skills, or a schedule that needs adjusting.
Signs Your Toddler Isn’t Getting Enough Sleep
The 11 to 14 hour range is a guideline, not a prescription, so watching your child’s behavior during the day is the best way to gauge whether they’re getting enough rest. A sleep-deprived toddler often looks hyperactive rather than tired. If your child seems unusually impulsive, melts down over small frustrations, or has trouble paying attention during play, insufficient sleep may be the reason.
Other signs include falling asleep on short car rides, low energy during times they’re normally active, frequent night waking with prolonged crying, and difficulty falling asleep despite being clearly exhausted. One or two rough nights is normal. A pattern lasting more than a couple of weeks is worth addressing.
Building a Bedtime Routine That Works
A consistent bedtime routine is one of the most effective tools for improving sleep at this age. Research from the Children’s Hospital of Philadelphia found that parents who followed a simple three-step routine (bath, massage, and quiet cuddling or singing) saw their children falling asleep faster and sleeping longer within two weeks. The children in that study ranged from 7 to 36 months old.
The specifics of your routine matter less than the consistency. A warm bath with dimmed lights, a short massage, a book or two, and then into the crib works well for most families. What helps the routine succeed is what happens around it: dimming lights in the house about 30 minutes before bed, turning off screens, keeping the bedroom between 66 and 72 degrees Fahrenheit, and using white noise if your child responds to it.
A comfort object like a small blanket or stuffed animal can also help your toddler self-soothe when they wake between sleep cycles at night. At 15 months, a lovey in the crib is generally considered safe, and many children this age become strongly attached to one. If your child doesn’t have a favorite yet, introducing one during the bedtime routine gives it a positive association with sleep.