Calculate the best bedtime based on 90-minute sleep cycles. Get browser reminders that work even when the tab is closed.
Users
2
−2 in 30 days
Rating
0.0 / 5
unchanged in 30 days
Ratings
0
0 in 30 days
Store rank
#360K
#273K among extensions
Version
1.0.0
updated 20 Apr 2026
Users
monthly, 6 months
Latest, 15 Oct 2026:2 usersMove the mouse over the chart for any month
Ratings count
monthly, 6 months
Latest, 15 Oct 2026:0 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About Bedtime Calculator — Sleep Cycle Timer
Stop waking up groggy. Time your sleep to the cycle — not the clock.
Most people think 8 hours of sleep is enough. It's not that simple. Waking up in the middle of a deep sleep cycle leaves you feeling worse than if you'd slept 7.5 hours and finished the cycle cleanly. The difference isn't how long you sleep — it's when your alarm goes off.
How the sleep calculator works:
Your brain moves through 90-minute sleep cycles all night. Each cycle includes light sleep, deep slow-wave sleep, and REM sleep. This extension counts backwards from your target wake-up time in 90-minute increments, adds 14 minutes for average sleep onset, and gives you the four best times to go to bed tonight.
Enter your wake-up time and get your ideal bedtime in one click.
