Sleep Calculator: What Time Should I Go to Bed?

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Sleep Tools

Sleep Calculator

What time should you go to bed? Work it out from 90-minute sleep cycles, see how much sleep your age group needs, and take a two-minute check on how well you are sleeping.

Step 1

When Should You Sleep?

Allows 15 minutes to fall asleep, the typical time for a healthy adult. A sleep cycle averages about 90 minutes but runs anywhere from roughly 70 to 120, so treat these as good starting points and adjust to how you feel.

Step 2

How Much Sleep Do You Need?

Age groupRecommended each night
Preschool (3–5)10–13 hours, naps included
School age (6–13)9–11 hours
Teenager (14–17)8–10 hours
Adult (18–64)7–9 hours
Older adult (65+)7–8 hours

Source: the US National Sleep Foundation’s recommendations (Hirshkowitz et al., 2015), which Australia’s Sleep Health Foundation uses. Some people do well on a little more or a little less.

Step 3

Is Your Sleep Healthy? A Two-Minute Check

Nine quick questions about a normal week. Your answers stay in your browser.

1. How long do you usually sleep on a work night?

2. How long does it usually take you to fall asleep?

3. How often do you wake in the night and struggle to get back to sleep?

4. Do you wake up feeling refreshed?

5. Do you feel sleepy during the day, in meetings or while driving?

6. Do you wake up with back, neck or shoulder pain?

7. How old is your mattress?

8. Do you sleep hot, or wake up sweaty?

9. Do you snore loudly, or has anyone noticed you stop breathing in your sleep?

Please answer all nine questions.

Better Sleep

Seven Habits That Help Most People

  • Keep the same wake-up time, weekends included. A steady wake time does more for your body clock than an early bedtime
  • Get daylight in the morning, and keep the evening dim
  • Stop caffeine by early afternoon, and keep alcohol modest; it helps you nod off but breaks up sleep later in the night
  • Put screens down for the last half hour and give yourself a wind-down routine
  • Keep the bedroom cool, dark and quiet. If you run hot, breathable bedding helps: see our bed sheets guide
  • Don’t lie there watching the clock. If you are still awake after about 20 minutes, get up and do something calm until you feel sleepy
  • Check your bed. A mattress that is too soft or too firm for how you sleep, or past its useful life, is a common reason for waking stiff or sore. Our mattress quiz takes a minute
FAQ

Sleep Calculator Questions

How accurate is a sleep calculator?
It is a good estimate, not a measurement. Sleep cycles average around 90 minutes but vary from person to person and through the night, and the time it takes to fall asleep changes too. Use the times as a starting point, then adjust by 15 minutes either way until you wake up feeling better.
Is 6 hours of sleep enough?
For most adults, no. The recommendation for 18 to 64 year olds is 7 to 9 hours. A few people genuinely do well on less, but if you are relying on caffeine to get through the afternoon, you are probably not one of them.
Why do I wake up tired after 8 hours?
Common reasons are waking in the middle of a deep sleep cycle, broken sleep you don’t remember, a bedroom that is too warm, or pain from a mattress or pillow that doesn’t suit you. Loud snoring with daytime sleepiness can be a sign of sleep apnoea, which is worth raising with your GP.
Can my mattress affect how well I sleep?
It can. A mattress that is too soft lets your hips sink and your back bend; one that is too firm presses on your shoulders and hips if you sleep on your side. Our guides match mattresses to back pain, side sleeping and sleeping hot.
How much sleep do teenagers need?
Eight to ten hours a night for 14 to 17 year olds. Teenagers’ body clocks also shift later, which is why early school starts are hard on them.

Continue your research

→ Take the Mattress Quiz → Best Mattress for Back Pain Australia → Best Mattress for Hot Sleepers Australia → Best Pillows Australia → Best Bed Sheets Australia

General information only, not medical advice. The sleep check is our own set of questions, not a clinical test; if sleep problems go on for more than a few weeks or affect your day, talk to your GP. Sleep durations: National Sleep Foundation (Hirshkowitz et al., 2015), as used by the Sleep Health Foundation.

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