Sleep planning
Sleep Duration and Bedtime Calculator
Calculate your available sleep opportunity or work backward from a wake time to a bedtime, including expected time to fall asleep.
- Runs only in your browser
- Nothing saved or added to the URL
- No account or email required
Your schedule
Calculate a sleep window
Times may cross midnight. Plans longer than 14 hours are not supported.
Calculated result
This is time available for sleep after your expected sleep latency—not measured sleep.
- Schedule
Method
What does the calculator do?
For an available sleep window, the calculator measures the time from bedtime to wake time across midnight, then subtracts the time you expect it will take to fall asleep.
For a bedtime, it adds your desired sleep duration and expected sleep latency, then counts backward from your wake time.
Limits
A window is not the same as actual sleep
The result is a sleep opportunity, not a measurement of sleep duration, sleep quality, or how rested you will feel. Awakenings and schedule changes are not included.
Sleep cycles vary. NHLBI describes cycles that restart about every 80 to 100 minutes, so this tool does not promise a refreshed wake-up based on fixed 90-minute blocks.
Adults generally need at least seven hours, but needs vary by age and person. Ongoing sleep concerns belong with a qualified health professional.
From a plan to a record
See the schedule beside the rest of your day
Grio lets you log sleep in conversation and view it alongside meals, workouts, weight, and supported Apple Health context. A calculator gives you a plan; your record shows what actually happened.
Sources and review notes
Content reviewed August 28, 2026
- NHLBI: Sleep Stages and Sleep Cycles Sleep stages and the roughly 80–100 minute cycle · accessed August 28, 2026
- CDC: About Sleep Sleep duration recommendations by age · accessed August 28, 2026