Sleep Calculator Tells You Precisely When To Hit The Hay For Maximum REM

If you're having trouble mastering your NREM-REM sleep cycle, it could be because you're choosing the wrong time to go to bed. (Earlier isn't necessarily better!) This handy web app calculates multiple bedtimes based on when you need to get up.

Sleep picture from Shutterstock

Like most people in the workforce, you could probably do with more sleep — but waking up at the right time is equally important. If your alarm goes off in the middle of an REM sleep cycle, you could actually end up feeling worse than if you'd stayed up.

Sleep Calculator is designed to help you master your body clock for the best sleep possible. What's great about this app is that it bases its calculations on sleep cycles to ensure you feel well rested upon waking; even if you didn't get a huge block of sleep.

For instance, if you need to be out of bed at 7am, Sleep Calculator suggests going to bed at either 9:46pm, 11:16pm, 12:46am or 2:16am. While the latter times will obviously result in less sleep, you'll be roused between REM cycles instead of being rudely awaken from a deep sleep. The result is that you'll feel relatively alert and refreshed, even if you only got a few hours' sleep.

The app's calculations also factor in an additional 14 minutes, which is how long the average person takes to fall asleep. If you find it difficult to doze off, just add some extra bedtime to the total. Try it for yourself here.

For more sleeping tips, check out our complete guide. Also be sure to check out our sleeper’s myth-busting guide and why it's healthy to sleep in the nude.

See also: How Much Sleep Do You Need To Feel Normal And Healthy?


    I've found the "90 minute" rule works... Think I also read that on lifehacker. Essentially, when you are getting up should be in 90 minute increments from when you go to sleep... (Or work backwards!). Easier to remember as well, don't need no calculator...

    Also... Seems the calculator may work on the same principle but allows for time to nod off, based on those times quoted

    Last edited 22/07/15 9:14 pm

    always have slept naked for years and still do now always felt it was better don't know why.

      Even in the winter???

      Last edited 22/07/15 10:12 pm

        sure do electric blankets keep the bed warm but i find for me nude has always been best.

          Me too, I don't have a lecky blanket, but still can't stand sleeping in clothes. I just pile another two blankets on top.

    Some basically just go to bed based on 90 minute intervals????
    Don't need an app for that.

    the only time this would help is when i'm drunk enough to sleep for a solid block between when i go to sleep and wake up

    Considering i can usually take anywhere between 30 to 90mins and no discernible pattern i'm SOL on this one.

    Interesting, will defs give this a try over a week. First three nights going to bed at the times suggested going from earliest to latest (skipping the 2:16am one cuz fuk dat). Next three back in the regular routine of sleeping when I think I should stop playing the xbox and see how I feel.

    Clicked for the header image, stayed for the article. Marketing. is just like that but it caters to other sleep calculations as well like " I want to go to sleep at the following time", and a convenient shorcut for "When do I wake up if I go to sleep now". - this one is mobile friendly with a better UI

    lifehacker, you really pick that photo for this article, petty pandering and what is the deal, are you trying to stay a site for white men? longtime reader, first time grossed out.

    There are more websites that helps you figure out when to go to sleep, to wake up in respect to the 90 minutes sleep cycles which has a positive influence on the quality of your sleep.

    I am sure there is some truth behind it. At the end of each cycle your body is more alert and susceptible to outside stimuli, making it easier to wake up as opposed to waking up from the “deep sleep” stage where your body is pretty much paralysed.

    Have a look at and play around with the go to bed, wake up times and try to follow it a day or two to respect that schedule, and see how you feel.

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