Bedtime Calculator
Tell us when you need to wake up and we will find the ideal time to go to bed tonight — based on 90-minute sleep cycle science.
Last updated: April 2026
If you fell asleep right now, your best wake times would be:
Format: HH:MM (e.g. 07:30)
How the Bedtime Calculator Works
The bedtime calculator works by reverse-engineering your sleep. You enter the time you need to wake up, and we work backwards in 90-minute blocks — the length of an average sleep cycle.
We then add 14 minutes to account for average sleep onset latency (the time it takes most adults to fall asleep). The result gives you four to six cycle options. Waking at the end of a cycle means your alarm sounds during light sleep, preventing the grogginess known as sleep inertia.
What is the Perfect Bedtime?
There is no single perfect bedtime for everyone, but there is a perfect bedtime for you. Finding it depends on three main factors: the total hours of sleep your body requires, your natural chronotype, and your daily schedule constraints.
Many people suffer from "bedtime drift" — pushing their sleep later each night while keeping a fixed morning alarm. This gradually erodes your sleep cycles, pulling you out of deep or REM sleep and leaving you exhausted. A perfect bedtime is one you can stick to consistently, allowing your circadian rhythm to lock in.
Bedtime by Age
Sleep requirements change as we age. Assuming a standard 7:00 AM wake time, here are the recommended bedtime ranges:
| Age group | Recommended hours | Bedtime range (7am wake) |
|---|---|---|
| Adults 18–64 | 7–9 | 9:45 PM – 11:45 PM |
| Adults 65+ | 7–8 | 10:45 PM – 11:45 PM |
| Teens 14–17 | 8–10 | 8:45 PM – 10:45 PM |
| School age 6–13 | 9–11 | 7:45 PM – 9:45 PM |
Chronotypes and Bedtime
Your chronotype is your body's natural inclination to sleep at a certain time. Sleep specialist Dr Michael Breus popularised four main chronotypes: the Bear (follows the sun), the Wolf (night owl), the Lark or Lion (early riser), and the Dolphin (light, irregular sleeper).
Forcing a Wolf to go to bed at 10:00 PM rarely works; they will likely lie awake frustrated. Similarly, a Lark will struggle to stay alert past 9:00 PM. The key is working with your chronotype, not against it. If your schedule allows, shift your wake time to accommodate a bedtime that feels natural to your biological clock.
Building a Wind-Down Routine
A good bedtime is supported by a solid wind-down routine. Think of it as a runway for your brain:
- 60 minutes before bed: Dim the lights and turn off bright overhead bulbs. This signals to your brain that it is time to start producing melatonin.
- 30 minutes before bed: Disconnect from work emails, stressful conversations, and doomscrolling. Switch to passive, relaxing activities.
- 15 minutes before bed: Get into bed and engage in a low-arousal activity, such as reading a physical book or practising slow breathing exercises.
Frequently Asked Questions
Ready to optimise your sleep further?
Try our Sleep Calculator to calculate backwards or forwards, or use the Sleep Cycle Calculator to check your recent sleep history.