Free calculator
Sleep calculator
How much sleep your age needs, and when to be asleep for the time you wake up. Worked out in your browser; nothing is sent anywhere.
Work out your sleep
Sleep to aim for
—a night
- Recommended for your age
- —
- Be asleep by
- —
- Start winding down
- —
- Last coffee by
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Enter your age to see how much sleep to aim for.
How it works
The ranges are the American Academy of Sleep Medicine's: 9–12 hours a night for children aged 6–12, 8–10 hours for teens, and 7 or more for adults. Fullday measures each night against 10, 9 or 8 hours, inside those ranges, until you set your own goal.
Need = 10 h (6–12) · 9 h (13–17) · 8 h (18+), or your own goal (at least 9 h under 13, 8 h for teens)
Be asleep by = wake-up − need · wind down 30 min before · last coffee 8.8 h before (adults)
A goal you set always wins, but a child's is held at 9 hours or more and a teen's at 8 or more, the bottom of their age's range. The 30 minutes is the app's default wind-down routine; a calm routine and steady bed and wake times are the NHLBI's healthy sleep habits. The coffee cut-off comes from a 2023 review of caffeine and sleep, and never appears under 18.
- Paruthi S, Brooks LJ, D'Ambrosio C, et al. (2016). Recommended amount of sleep for pediatric populations: a consensus statement of the American Academy of Sleep Medicine. Journal of Clinical Sleep Medicine, 12(6), 785–786. doi.org/10.5664/jcsm.5866
- Watson NF, Badr MS, Belenky G, et al. (2015). Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep, 38(6), 843–844. doi.org/10.5665/sleep.4716
- Gardiner C, Weakley J, Burke LM, et al. (2023). The effect of caffeine on subsequent sleep: a systematic review and meta-analysis. Sleep Medicine Reviews, 69, 101764. sciencedirect.com
- National Heart, Lung, and Blood Institute (2022). Healthy sleep habits. National Institutes of Health. nhlbi.nih.gov
Questions
How much sleep do I need?
Adults need 7 or more hours a night (AASM and Sleep Research Society), teens 8–10 hours and children aged 6–12 9–12 hours (AASM). Fullday aims for 8, 9 and 10 hours until you set your own goal.
What time should I go to bed?
Count your sleep need back from the time you have to get up. To wake at 6:30 am with an 8-hour need, be asleep by 10:30 pm, and start a calm wind-down around 10:00 pm. Going to bed and getting up at the same times every day helps too.
When should I stop drinking coffee?
A 2023 review found a cup of coffee should be finished about 8.8 hours before bed to avoid cutting into sleep, and a large dose of 200 mg or more about 13.2 hours before. Fullday doesn't time caffeine for anyone under 18.
What if I sleep this long and still feel tired?
Talk to a doctor. Loud snoring, gasping at night, trouble falling or staying asleep, or feeling sleepy during the day despite enough time in bed can be signs of a sleep problem worth checking.
Fullday tracks this for you every day.
Its sleep score measures every night against this same sleep need. Coming to the App Store this December, free to download.
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