# The exact time you should go to sleep if you need to wake up at 7am; With the handy information now readily available, groggy mornings need not be a regular occurrence anymore.

Byline: James Rodger

It turns out there's an exact time you need to go to sleep - depending on what time you need to wake up for work feeling suitably refreshed.

With the handy information now readily available, groggy mornings need not be a regular occurrence anymore.

You see, someone has created a 'sleep calculator' so we can work out when we need to hit the sack in the click of a button.

Apparently it's all to do with sleep cycles rather than getting more hours of sleep, asMirror Onlinereports.

If you wake up at the wrong time during a sleep cycle, you'll find yourself more tired - even if you were asleep for longer.

Need to make sure you're awake and getting out of bed at 7am?

Then you need to go to bed at either 9.46pm or 11.16pm.

If you're having a late night and you don't fancy either of these, then 12.46am and 2.16am will also work.

The sleep calculator factors in the average of 14 minutes it takes people to naturally fall asleep, so you don't necessarily need to be in bed by this time.

To get up at 6am, you're looking at a bedtime of 8.46pm, 10.16pm or even 11.46pm or - if you're feeling like a real night owl - 1.16am.

Don't need to get up super early to get to work on time?

Have no fear.

Here's what time you need to go to bed for an 8am rise: 10.46pm, 12.16am, 1.46am or 3.16am.

For example, if you know getting out of bed at 6.35am is the optimum time so you can not miss the train and be punctual for work, enter it into the sleep calculator and you'll get a result.

For a 6.35am rise time, go to bed at 9.21pm, 10.51pm, 12.21am or 1.51am.

The Sleep Calculator website reads: "Getting a good night's sleep is about more than simply going to bed early -- it's about waking up at the right time too.

"Using a formula based on the body's natural rhythms, the Sleep Calculator will work out the best time for you to rise or go to sleep."

The calculator works on the principle that everyone sleeps in about five or six cycles which last roughly 90 minutes.

Waking up midway through a cycle can leave you feeling grumpy the next day.

The idea is to wake up in between cycles and feel refreshed in the morning.

CAPTION(S):

Credit: (c) Spauln