This amazing sleep calculator tells you EXACTLY when you should be in bed

A new sleep calculator claims to be able to tell you the exact minute you need to enter the land of nod to ensure you wake up refreshed and ready to take on the world.

The tool rebuffs the idea that getting an early night in is the best way to achieve the optimum amount of shut-eye, suggesting instead that all we need to really know is when to latch on to the start of a new sleep cycle so we wake up at the end of one - and avoid that groggy feeling, the Daily Mail reports.

Sleep for an average adult occurs in 90-minute cycles, meaning we go through five or six a night. Waking mid-way through a cycle can leave you feeling more tired.

 The calculator counts back from the time a person needs to wake in 90 minute cycles and takes into account a "15 minute dropping off period".

So, if you need to be at the office by 9:00am, rising at 8am, it advises that you either go to bed at 10:46pm or wait for the next cycle to begin at 12:16am.

The creators, blind retailer Web Blinds, explain: "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."

This article was first published on Daily Mail and is republished here with permission.