This sleep calculator can function either as a bedtime calculator or a wake up tool that helps you monitor how much sleep you get. You can read more on this subject and discover some interesting sleep facts below the form.


Desired wake up time: *
Average time to fall asleep:
Desired time to sleep:
Bedtime: *
Average time to fall asleep:
Desired time to sleep:

How does this sleep calculator work?

This is a two in one sleep calculator because it can act as a bedtime calculator that helps you estimate when to fall asleep or as well as a wake up calculator because can estimate when you should set up your alarm if you go to sleep now or at a certain hour.

Before explaining how the sleep calculator works it is important to notice that a correct time to go to sleep and a correct time designated to sleep is a part of lifestyle that finally has impacts on your health and overall condition.

  • The first tab is called the “Bedtime Calculation” and is designed to help you estimate when to fall asleep if you want to wake at a certain hour. In this tab you will find 3 fields to fill in your data, as presented below:

-Desired wake up time is a mandatory field in which you can choose the time to wake up. Select from the drop down list the desired hour to wake up, desired minute to wake up and the AM/PM depending on your local time.

-Average time to fall asleep is an optional field in which you choose to specify a customized time you need to fall asleep in minutes. If this field is left blank an average of 15 minutes time to fall asleep is taken into account.

-Desired time to sleep is an optional field in which you can choose how much time you would like to sleep in hours. If this field is left blank an average of 8 hours to sleep is taken into account.

  • The second tab is the “Wake up Calculation” and is designed to help you estimate when you should wake up if you go to sleep now or at a certain hour. In this tab you will find 3 fields(first is mandatory, the other 2 are optional) to fill in data, as presented below:

-Bedtime is a mandatory field in which you can choose the time you are about to go to bed. The bedtime is default settled to now. But you can select from the drop down list the desired hour to go to sleep, the desired bedtime minute and the AM/PM depending on your local time.

-Average time to fall asleep is an optional field in which you choose to specify a customized time you need to fall asleep in minutes. If this field is left blank an average of 15 minutes time to fall asleep is taken into account.

-Desired time to sleep is an optional field in which you can choose how much time you would like to sleep in hours. If this field is left blank an average of 8 hours to sleep is taken into account.

The results displayed by the tool above depend on the tab you choose to calculate. So, if you choose to calculate bedtime it will return you when you should go to bed in order to wake up at a certain hour. While if you choose to calculate wake up time it will return you the wake up if you go to bed at a certain hour.

Example of a calculation and result:

  • First tab: Desired wake up at 7:35am, the average time to fall asleep 10 minutes and the desired time to sleep 8h. The result says you should go to sleep at 11:25pm.
  • Second tab:Bedtime is at 11:45pm, the average time falling asleep is 15 minutes and the desired time to sleep is 8.5 hours. The result says you need to set your alarm clock at 8:30am.

How much sleep do you really need?

According to some data released by the National Sleep Foundation, the time we need to sleep depends on the age group. Below is presented the table with how much people need to sleep:

Age Sleep Needs
Newborns (0 - 2 months) 12 - 18 hours
Infants (3 - 11 months) 14 - 15 hours
Toddlers (1 - 3 years) 12 - 14 hours
Preschoolers (3 - 5 years) 11 - 13 hours
School-age children (5 - 10 years) 10 - 11 hours
Teens (10 - 17 years) 8.5 - 9.25 hours
Adults (18 years or more) 7 - 9 hours

Source of the table: National Sleep Foundation

The average falling asleep time is somewhere between 7 – 14 minutes and may vary from one day to another due to different contextual sleeping conditions and/or different factors encountered during the day before sleep time. There are nights in which people fall asleep in hours due to stress or overloading of their mind, but that is not unusual because these kinds of situations may appear at least one time in life. Falling asleep in hours night by night may came unusual, as a disruption of standard functions.

19 Mar, 2015