What the sleep score means and how to improve it

The Lulla Sleep Score is a number from 0 to 100 that tells you how well your baby slept today. It's not a judgment — it's a tool for understanding.

The 6 components

Duration (30 points) — How close the daily sleep total is to the National Sleep Foundation range for your baby's age. What gets scored is the sleep day: the night that started after 6:00 PM the previous evening, plus today's naps, so in the morning the total is still incomplete. The range is 14-17 hours at 0-3 months, 12-15 hours at 4-11 months and 11-14 hours at 1-2 years. Inside the range you get all 30 points; below or above it, you lose points in proportion to the distance: a newborn who sleeps 12 hours gets 26 out of 30. It's a reference point, not a diagnosis: a newborn who sleeps less can be perfectly healthy.

Rhythm (20 points) — Compares the start times of the night sleeps logged within the same sleep day (a sleep counts as night sleep if it started between 8:00 PM and 7:00 AM). With a single night sleep you get 12 points; if the night is logged in several pieces, the score drops the further apart the pieces start, down to 0 at an average deviation of two hours. With no night sleep, 0. It doesn't compare bedtime from one evening to the next.

Night/day ratio (15 points) — The maximum score comes when 65-90% of sleep happens at night. In the first months it's normal for it to be less: in a diary study, about 60% of sleep fell at night at six weeks, and that share grows on its own with age.

Quietness (10 points) — Fewer wake-ups = higher score. 0 wake-ups = 10/10.

Quality (15 points) — The rating you give at the end of each session (1-5 stars).

Mood (10 points) — How your baby wakes up. "Happy on waking" = 10/10. "Fussy" or "Crying" = lower score.

What's a good score?

• 85-100: Excellent — Congratulations! The routine is working perfectly.
• 70-84: Very good — Small adjustments can make the difference.
• 55-69: Good — The basics are solid, but there's room for improvement.
• 40-54: Could be better — Focus on the weakest component.
• Under 40: Needs attention — Read the personalized advice in Lulla.

3 quick strategies for +15 points

1. Keep the same bedtime (±15 min) for 7 days in a row — that's exactly what makes a solid bedtime routine.

2. Complete the review after every session — quality and mood are 25 free points.

3. Log every sleep, including sleep in your arms, in the carrier or in the stroller: an unlogged sleep lowers “Duration” without your baby having slept any less. Don't cut daytime naps to raise the night/day ratio: in a newborn, you don't cut daytime sleep.