Sleep duration
How long you were actually asleep, as estimated by your Apple Watch, naps included. Lying awake in bed doesn't count.
Apple Watch estimates sleep from the small movements its motion sensor picks up, breathing included, and saves each night to Apple Health. Pajdo adds up the time asleep across every stage and counts it on the day you wake up. Naps join the total too.
For adults 18 to 60, the American Academy of Sleep Medicine and the Sleep Research Society recommend 7 or more hours a night on a regular basis. The National Sleep Foundation suggests 7–9 hours from 18 to 64 and 7–8 hours from 65. Some people do fine near the low end, others need the top.
Caffeine is a big mover. In a review of 24 studies it cut total sleep by about 45 minutes on average, and the later it was taken, the bigger the cut. Regular exercise nudges sleep time up a little.
Pajdo compares your last 3 nights with your own usual, so one late movie won't change his mood. He only notices a gap of at least 30 minutes that sits well outside your typical spread.
What tends to push it up
- Regular exercise, by a little
- Catching up after a run of short nights
What tends to pull it down
- Caffeine in the afternoon or evening
Worth a try
Keep your sleep times steady
The NHS says going to bed and getting up at similar times each day makes it easier to fall asleep. The American Academy of Sleep Medicine suggests getting up at the same time every day, even on weekends. A National Sleep Foundation expert panel agreed that regular sleep timing matters for health and performance.
Pajdo's bedtime consistency shows how much your bedtime has moved around over the last week, using sleep from Apple Health.
Try it: pick a wake-up time you can keep all week, set an alarm, and let bedtime settle around it.
Make your bedroom cool and dark
The NHS, the American Academy of Sleep Medicine and the National Sleep Foundation all point the same way: a bedroom that's quiet, dark and comfortably cool. The NSF notes the best temperature differs from person to person.
Small fixes go a long way. Blackout curtains or an eye mask for light, earplugs or gentle background sound for noise.
Try it: tonight, close the curtains fully, turn your phone face down on silent, and make the room a touch cooler than usual. Tweak one thing at a time until it feels right.
Give your evening a slow finish
The NHS says a calm bedtime routine can help you prepare for sleep, and suggests reading, breathing exercises or calming music. The American Academy of Sleep Medicine recommends a relaxing routine and limiting bright light in the evening. The National Sleep Foundation suggests dimming the lights as bedtime gets closer.
Try it: pick a wind-down start time before your usual bedtime. Dim the lights, put your phone to bed somewhere out of reach, and do the same calm thing each night so it becomes a cue.
Keep reading
Sources
- Recommended amount of sleep for a healthy adult: a joint consensus statement, American Academy of Sleep Medicine and Sleep Research Society (J Clin Sleep Med, 2015)
- National Sleep Foundation's updated sleep duration recommendations: final report, National Sleep Foundation (Sleep Health, 2015)
- Track your sleep on Apple Watch and use Sleep on iPhone, Apple
- The effect of caffeine on subsequent sleep: a systematic review and meta-analysis, Sleep Medicine Reviews (Gardiner et al., 2023)
- The effects of physical activity on sleep: a meta-analytic review, Journal of Behavioral Medicine (Kredlow et al., 2015)
- How to fall asleep faster and sleep better, NHS Every Mind Matters
- Healthy Sleep Habits, American Academy of Sleep Medicine
- The importance of sleep regularity: a consensus statement of the National Sleep Foundation (Sletten et al. 2023), Sleep Health
- How to Make a Sleep-Friendly Bedroom, National Sleep Foundation
Checked against these sources on September 15, 2026.
This is general wellness information, not medical advice. If a number worries you, or stays away from your usual for a while, talk to a doctor.