18 month sleep regression

When
Usually between 17 and 20 months
How long
Often 2–6 weeks
Typical wake window
4.5–6 h
Typical naps
1

Why it happens

  • A second peak of separation anxiety.
  • Growing independence and the desire to test limits.
  • Molars and language bursts at the same age.

Common signs

  • Bedtime battles and stalling
  • Refusing the nap
  • Waking at night and calling out

What helps

  • Keep the same routine in the same order every night.
  • Offer limited choices (which pajamas, which book) to give a sense of control.
  • Don't drop the nap in response; most 18 month olds still need one.
  • Hold calm, predictable limits.

Call your pediatrician if your baby has a fever, seems unwell, is feeding poorly, snores loudly or pauses in breathing, or if the disruption lasts more than a few weeks.

A steady daytime rhythm makes rough nights easier to ride out. Here's a typical day for this age:

18 month old schedule

Plan the day from
Wake windows
5 h → 5 h 30 min
Daytime sleep
2 h
Night in bed
11 h 30 min
Typical 24 h total
11–14 h (incl. naps)

Your day at a glance

12a3a6a9a12p3p6p9p
Night sleepNapsAwake
  1. 7:00amWake up for the day
  2. 12:00pm–2:00pmNap 1 · 2 h
  3. 7:30pmBedtime · start routine 7:00pm

A flexible guide built from typical ranges. Watch your baby's sleepy cues and shift by 15–30 minutes as needed. Every sleep: on the back, in a clear, flat crib (AAP).

Questions

When does the 18 month sleep regression start?

Usually between 17 and 20 months.

How long does the 18 month sleep regression last?

Often 2–6 weeks.

Should I move my toddler to a bed during the 18 month regression?

Most sleep experts suggest keeping a toddler in the crib as long as it's safe, often until closer to age 3. Big changes during a rough patch can make things harder.

Other guides: 4 month sleep regression · 8 month sleep regression