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🌙 Sleep Calculator

Find a realistic bedtime or wake time — including the time it takes you to fall asleep
⚡ Quick Start
➤Calculate when to get in bed from a wake time, or when to wake from a bedtime
➤Choose your age, sleep goal, sleep-onset time, and expected time awake overnight
➤Get one main plan plus the full age-based sleep window
A useful sleep plan includes more than hours asleep
The calculator adds your expected time to fall asleep and time awake during the night, then shows how the result fits your age-based sleep range.
The time you need to be awake and out of bed.
Used to set the planning range, not to predict your exact personal need.
Actual time asleep, excluding the time needed to fall asleep or periods awake overnight.
Your usual estimate from getting into bed to falling asleep.
Optional allowance for awakenings after you first fall asleep.

Your Sleep Plan

Get in bed by
10:45 p.m.
Sleep goal: 8 hrs
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Get in bed
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Estimated sleep
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Wake up
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Actual sleep goal
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Total time in bed
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Age-based guide
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Other Times Within Your Age Range

How the calculation works

This calculator plans a sleep opportunity; it cannot know exactly how long you will sleep or how rested you will feel. Individual sleep need varies. Sleep-cycle length also varies across the night, so the times are based on sleep duration and your allowances—not a promise that waking at a specific cycle boundary will feel easier.
📊 Recent Calculations
📖 Detailed Instructions & Calculation Method

Two calculation directions: Choose “I need to wake at…” when your morning time is fixed. Choose “I plan to get in bed at…” when your bedtime is fixed and you want a wake-time estimate.

What the calculator adds:

Age ranges: The calculator uses published consensus ranges: 9–12 hours for ages 6–12, 8–10 hours for ages 13–18, 7–9 hours for adults 19–64, and 7–8 hours for adults 65 and older. The child and teen ranges apply across the full 24 hours, so naps count toward the total. These are population guides, not an exact requirement for every person.

Why it does not use exact 90-minute blocks: Adult sleep cycles commonly recur roughly every 80–100 minutes, and their length and composition change through the night. A fixed 90-minute formula can look more precise than the evidence allows.

Research sources: See the AASM pediatric sleep-duration consensus, the adult and older-adult duration recommendations, and the NHLBI overview of sleep-cycle timing.

Privacy and history: No login is used. Completed calculations are stored only in this browser. Changing the inputs without calculating saves nothing.