Sleep

When should you actually go to bed?

Work backwards from your wake time in sleep cycles, then see the debt your week is quietly accumulating.

What this tool is

This tool works backwards from the time you need to wake up in 90-minute cycles, allowing 15 minutes to fall asleep, and gives you four candidate bedtimes. A second part compares your weeknight and weekend hours against a weekly target and shows the shortfall you are carrying.

Takes: Under a minute
You need: Nothing but your details

What you get

Four bedtimes, from three to six sleep cycles
Hours of sleep for each option, with the ones meeting seven hours marked
Your weekly sleep total against a weekly target
Your accumulated debt and the nightly shortfall behind it

How to use it

01Enter the time you need to be awake.
02Choose a bedtime that gives you seven hours or more.
03Enter your typical weeknight and weekend hours to see the weekly debt.
04Move your bedtime earlier rather than trying to repay the debt at the weekend.

To wake at 6:30 am, fall asleep by

9:15 pm6 cycles · 9 hoursMeets adult guidance
10:45 pm5 cycles · 7.5 hoursMeets adult guidance
12:15 am4 cycles · 6 hoursBelow 7 hours
1:45 am3 cycles · 4.5 hoursBelow 7 hours

What this cannot tell you

The 90-minute cycle is a planning average, not a fixed constant: real cycles vary between people and across the night. Sleep opportunity is only part of sleep quality, and no calculator can rule out a sleep disorder.

Sources

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