Most 20-month-olds do best with a bedtime between 7:00 and 8:00 p.m., though the right time for your child depends on when they need to wake up and how long they nap. Toddlers this age need 11 to 14 hours of total sleep per day, including naps, a range endorsed by both the American Academy of Pediatrics and the Cleveland Clinic. The simplest way to find your child’s ideal bedtime is to work backward from their morning wake time.
How to Calculate Your Child’s Bedtime
Start with the time your child needs to be awake in the morning. Subtract 11 to 12 hours of nighttime sleep, and that’s your target bedtime. If your toddler wakes at 6:30 a.m., aim for lights out between 6:30 and 7:30 p.m. If they sleep until 7:30 a.m., an 8:00 p.m. bedtime can work. The exact number of nighttime hours your child needs will vary. Some 20-month-olds sleep 10.5 hours at night and make up the rest with a longer nap, while others consistently sleep 11 or 12 hours overnight and take a shorter nap.
If your child regularly takes a while to fall asleep after you put them down, factor that in. A toddler who takes 15 to 20 minutes to drift off after being placed in the crib should be put down that much earlier than your target “asleep by” time.
How Naps Shift Bedtime
At 20 months, most toddlers are on a single midday nap, ideally falling somewhere between 12:00 and 3:00 p.m. That nap typically lasts one to three hours. The timing and length of this nap directly affect when your child will be ready for sleep at night.
A nap that ends at 1:30 p.m. leaves plenty of awake time before a 7:00 p.m. bedtime. But if your toddler sleeps until 3:30 or 4:00 p.m., they probably won’t be tired enough to fall asleep at 7:00. In that case, you can either cap the nap earlier or push bedtime slightly later. Putting a child down too late for a nap is one of the most common reasons toddlers resist bedtime, according to Boys Town National Research Hospital. If naps are consistently running late, try shifting the start time earlier by 15 minutes every few days.
Most 20-month-olds need about four to five hours of awake time between the end of their nap and bedtime. If the gap is shorter, expect some protest at lights out. If it’s much longer, you risk overtiredness, which creates its own problems.
Why a Late Bedtime Backfires
Parents sometimes assume that keeping a toddler up later will make them sleep longer in the morning. It usually does the opposite. A study of two-year-olds published in the Journal of Physiological Anthropology found that children with habitually delayed bedtimes had shorter total sleep, more irregular sleep schedules, and greater difficulty both falling asleep and waking up. They also showed more bedtime resistance and morning irritability.
The pattern tends to reinforce itself. A toddler who goes to bed late sleeps less overall, compensates with a longer or later daytime nap, and then isn’t tired at bedtime the next night. Breaking that cycle usually means pulling bedtime earlier, even if it feels counterintuitive, and capping the daytime nap so it doesn’t push past mid-afternoon.
Signs You’re Missing the Window
Overtired toddlers don’t always look sleepy. In fact, they often look wired. A 20-month-old who is running around the living room with sudden bursts of energy at 7:30 p.m. may actually be past the point of easy sleep. Other signs of overtiredness include:
- Clinginess that wasn’t there an hour ago
- Eye rubbing and yawning mixed with resistance to being held or put down
- Irritability or crying over things that don’t normally bother them
- Hyperactivity around naptime or bedtime
If you’re seeing these signs regularly, try moving bedtime 15 to 30 minutes earlier for a week and see if the behavior shifts. Many parents find their toddler actually falls asleep faster with an earlier bedtime because they’re catching the natural window of drowsiness instead of pushing past it.
Sleep Disruptions Around This Age
If your 20-month-old was sleeping well and suddenly isn’t, you may be dealing with the tail end of the 18-month sleep regression. This is one of the more challenging regressions, and it can stretch into the 20- to 21-month range for some children. Common signs include fussiness at bedtime, new nighttime awakenings, and strong resistance to being put in the crib.
Several things converge around this age to disrupt sleep. Toddlers are gaining physical skills rapidly, and all that new mobility can make them restless. Their emotional world is also expanding. Separation anxiety, which many toddlers first experience around 15 to 18 months, can intensify during this period. Separations feel harder when children are tired, hungry, or sick, and bedtime checks all those boxes. Teething (particularly molars) and a growing sense of independence also play a role.
Sleep regressions are temporary. Keeping bedtime consistent, even when your child protests, helps them move through it faster. The routine matters more than the specific time on the clock, but maintaining a predictable schedule gives your toddler an anchor during a developmentally chaotic stretch.
Building a Bedtime That Sticks
Consistency matters more than precision. A bedtime that varies by 15 minutes from night to night is fine. One that swings by an hour or more creates the kind of irregularity linked to sleep problems in toddlers. Pick a target time based on your child’s wake time and nap schedule, then keep it within a narrow range.
A short, predictable routine before bed helps signal that sleep is coming. At 20 months, this doesn’t need to be elaborate: a bath, a book, a song, and into the crib is plenty. The whole sequence can take 20 to 30 minutes. What matters is that it happens in roughly the same order each night, so your toddler’s body starts associating those cues with winding down. If your child is showing signs of separation anxiety at bedtime, a calm and brief goodbye ritual (the same words and actions every night) helps more than prolonged soothing, which can accidentally reinforce the anxiety.