To avoid feeling tired when waking up.

For many people, going to bed early is always a real challenge. Every morning, you wake up feeling tired and resolve to go to bed early tonight. But then, by the time you finally look away from your computer screen, it's already past midnight.

The latest report from the Great British Bedtime Sleep Council shows that 74% of Britons sleep less than 7 hours a night, and the number of people sleeping less than 5 hours has risen from 7% to 12%.

61% of the 5,002 participants in the 2017 survey stated that 5-7 hours is the standard for nighttime sleep.

We all know how important sleep is every day. New studies show that more sleep will make us happier/slimmer/richer/healthier/better.

But most accept that there are differences in the amount of “eye rest.” While some would be very tired if they slept less than 9 hours, others would be comfortable with just over 4 hours of sleep.

So how do you know when you should sleep? The key is not to worry about how long you sleep, but to focus on your sleep cycle.

"The brain has its own sleep pattern. It's not like you, it doesn't count whether you sleep 1 hour or 2-3-5-9 hours. The brain's sleep is cyclical, from non-REM sleep to REM sleep," explains expert Laura Lefkowitz.

To ensure you wake up feeling refreshed, just make sure you're not woken up in the middle of a cycle – each sleep cycle lasts about 90 minutes, and ideally you sleep 5-6 cycles.

Waking up in the middle of your cycle will leave you feeling irritable and tired; waking up at the right time will allow you to start the day feeling refreshed.

One way to know when you should go to bed is to use a sleep cycle calculator. You enter your desired wake-up time and it will show you what times you can go to bed.

This calculation is based on the fact that the average person takes 14 minutes to fall asleep; of course, you may not be one of them.

Sleep tracking apps aren't new, but they're a way to avoid waking up in the middle of your sleep cycle while also serving as smart alarms, helping you wake up feeling refreshed.

According to Dantri