41 free tools for sleep timing, sleep need, your body clock and your bedroom. Pick a tool, enter a few details and get an answer in seconds, with the method and sources shown on every page.
Start with the Sleep CalculatorFind your best bedtime or wake-up time from 90-minute sleep cyclesOpen- Free, no sign-up
- Runs in your browser
- Formulas and sources shown
- 48 calculators
Popular Sleep Calculators
The tools people use most, by search clicks and by what they answer.
- PopularTiming
Bedtime Calculator
Bedtimes that end on a full sleep cycle for your wake-up time.
Calculate now - PopularTiming
Sleep Cycle Calculator
Best wake-up times after 4, 5 or 6 cycles from your bedtime, or from right now. Includes how to find your own cycle length.
Calculate now - PopularBedroom
Pillow Height Calculator
Your ideal pillow height from sleep position, shoulder width and mattress.
Calculate now - PopularBody clock
Shift Work Sleep Calculator
When to sleep, nap and stop caffeine around night, early and rotating shifts.
Calculate now - PopularTracking
Sleep Debt Calculator
Your weekly sleep debt and a realistic plan to pay it back.
Calculate now - PopularTiming
Polyphasic Sleep Calculator
Clock times and real sleep totals for biphasic and polyphasic schedules.
Calculate now
Sleep Timing
When to go to bed, when to wake up and when to nap.
- Timing
Bedtime Calculator
Bedtimes that end on a full sleep cycle for your wake-up time.
Calculate now - Timing
Sleep Cycle Calculator
Best wake-up times after 4, 5 or 6 cycles from your bedtime, or from right now. Includes how to find your own cycle length.
Calculate now - Timing
Nap Optimization Calculator
The best nap length and time for your goal, from 20 to 90 minutes.
Calculate now - Timing
Sleep Inertia Calculator
How long morning grogginess may last, and how to time alarms and naps.
Calculate now - Timing
Polyphasic Sleep Calculator
Clock times and real sleep totals for biphasic and polyphasic schedules.
Calculate now
Sleep Need And Tracking
How much sleep you need, how much you get, and how regular it is.
- Tracking
Sleep Calculator By Age And Gender
Recommended hours of sleep for every age, from newborns to over 65.
Calculate now - Tracking
Sleep Duration Calculator
How long you actually slept last night, or your average over a week.
Calculate now - Tracking
Sleep Debt Calculator
Your weekly sleep debt and a realistic plan to pay it back.
Calculate now - Tracking
Chronic Sleep Deprivation Risk Calculator
Whether short sleep has become a long-term pattern, from your week and daytime signs.
Calculate now - Tracking
Sleep Statistics Calculator
Weekday vs weekend gap, night-to-night variation and lifetime sleep totals.
Calculate now - Tracking
Sleep Consistency Calculator
Your Sleep Regularity Index and social jetlag from a week of times.
Calculate now - Tracking
Sleep Score Calculator
A score for last night from your sleep and wake times, with a 7-day history.
Calculate now - Tracking
Sleep Quality Calculator
Rate seven aspects of your usual sleep and get an action plan.
Calculate now - Tracking
REM Sleep Calculator
Estimated REM and deep sleep, and when your REM periods happen.
Calculate now - Tracking
Calories Burned Sleeping Calculator
Calories you burn while asleep, using the Mifflin-St Jeor equation.
Calculate now - Tracking
Sleep Stage Percentage Calculator
Check your tracker deep sleep and REM against adult ranges.
Calculate now - Tracking
Sleep Latency Calculator
Your average time to fall asleep and where it sits.
Calculate now
Body Clock, Shifts And Travel
Fit sleep around your body clock, your work hours and new time zones.
- Body clock
Sleep Schedule Reset Calculator
A day-by-day plan to move your bedtime and wake time back to where you want them.
Calculate now - Body clock
Circadian Rhythm Calculator
Your chronotype, social jetlag and natural sleep window, with a 24-hour chart.
Calculate now - Body clock
Shift Work Sleep Calculator
When to sleep, nap and stop caffeine around night, early and rotating shifts.
Calculate now - Body clock
Jet Lag Recovery Calculator
Days to adjust after crossing time zones, and when to seek or avoid light.
Calculate now - Body clock
Caffeine Impact On Sleep Calculator
Caffeine left at bedtime and the latest time for your last coffee.
Calculate now - Body clock
Blue Light Exposure Calculator
Score your evening screen and light exposure and get a plan to cut it.
Calculate now - Body clock
Night Calculator
Count the nights between two dates for a trip or stay, and the sleep it allows.
Calculate now - Body clock
Daylight Saving Time Sleep Calculator
A night-by-night plan to prepare for the clocks changing.
Calculate now - Body clock
Daily Caffeine Intake Calculator
Add up your drinks and compare with the published daily limit.
Calculate now
Sleep Health Checks
Screening tools that show when a sleep problem is worth raising with a doctor.
- Health check
Insomnia Severity Calculator
Whether your bad nights match short-term or chronic insomnia.
Calculate now - Health check
Sleep Efficiency Calculator
How much of your time in bed is spent asleep, plus a starting sleep window used in CBT-I.
Calculate now - Health check
Sleep Apnea Risk Calculator
Sleep apnea risk from snoring, breathing pauses and other risk factors.
Calculate now - Health check
Sleep Paralysis Risk Calculator
Factors linked to sleep paralysis and which to change first.
Calculate now - Health check
Sleep Tension Calculator
Whether a busy mind or a tense body keeps you awake, and what helps.
Calculate now - Health check
Perimenopause And Menopause Sleep Calculator
What is disrupting sleep in perimenopause or menopause, and the next step.
Calculate now - Health check
Sleep Disorder Probability Calculator
A general check of your sleep symptoms when you are not sure where to start.
Calculate now - Health check
AHI Calculator
Sleep apnea severity from the events and hours on your sleep report.
Calculate now
Babies, Kids And Teens
Age-specific tools for parents.
- Family
Baby Sleep Calculator
Nap times, wake windows and bedtime for babies aged 0 to 35 months.
Calculate now FamilyBaby 24-Hour Sleep Calculator
Log night sleep and naps to check the total against the recommended range.
Calculate now FamilyToddler Sleep Schedule Calculator
Nap window, bedtime and total sleep plan for ages 2 to 5.
Calculate now - Family
Adolescent Sleep Deficit Calculator
How much sleep a teenager misses on school nights, and a plan to close the gap.
Calculate now
Bedroom And Sleep Products
Choose and set up your pillow, mattress and bedroom.
- Bedroom
Pillow Height Calculator
Your ideal pillow height from sleep position, shoulder width and mattress.
Calculate now - Bedroom
Mattress Calculator By Sleep Position And Weight
Mattress firmness, type and thickness for your position and weight.
Calculate now - Bedroom
Mattress Age Impact Estimator
Whether your mattress is old enough that replacing it may help.
Calculate now - Bedroom
Sleep Temperature Calculator
The best bedroom temperature for adults, older adults and babies.
Calculate now - Bedroom
Weighted Blanket Calculator
A starting weighted blanket weight from your body weight, with safety checks.
Calculate now - Bedroom
White Noise Benefit Calculator
Whether white noise may help, based on your bedroom noise.
Calculate now - Bedroom
Sleep Accessory ROI Calculator
Cost per night of a mattress, pillow or other sleep product.
Calculate now
Just For Fun
Light-hearted tools. They are not health advice.
Which Sleep Calculator Should I Use?
| Your situation | Start with |
|---|---|
| I know when I need to wake up | Bedtime Calculator |
| I know when I will go to bed, or I am going to sleep now | Sleep Cycle Calculator |
| I want to know if I sleep enough | Sleep Duration Calculator |
| I have been short of sleep for a while | Sleep Debt Calculator |
| I work nights or rotating shifts | Shift Work Sleep Calculator |
| I snore or wake up gasping | Sleep Apnea Risk CalculatorFamilyBedtime Routine PlannerTimed plan from bath to lights out Plan now EnvironmentBed Height CalculatorFind your ideal mattress height Calculate now NapsCoffee Nap CalculatorTime your coffee and nap combo Calculate now SafetyHours Awake CalculatorCheck your fatigue level Calculate now |
How These Calculators Work
Method Shown
Every calculator states its formula and assumptions, with a worked example.
Sources Cited
Ranges and thresholds come from the National Sleep Foundation, the NHLBI, MedlinePlus and peer-reviewed studies.
Private By Design
Calculations run in your browser. Nothing you enter is sent to us.
Sleep Calculator FAQs
Which sleep calculator should I use?
If your wake-up time is fixed, use the Bedtime Calculator. If your bedtime is fixed or you are going to sleep now, use the Sleep Cycle Calculator. To check whether you sleep enough, use the Sleep Duration Calculator.
Are these sleep calculators free?
Yes. Every calculator is free, needs no sign-up and runs in your browser.
How accurate are sleep calculators?
The arithmetic is exact, but results rely on published formulas and population averages, such as 90-minute sleep cycles. Your own sleep varies from night to night, so treat results as a guide.
How many hours of sleep do I need?
Most adults need 7 to 9 hours, teens 8 to 10 and school-age children 9 to 11, according to the National Sleep Foundation. The Sleep Calculator by Age and Gender covers every age group.
Can a sleep calculator diagnose a sleep disorder?
No. Screening tools such as the Sleep Apnea Risk Calculator and the Insomnia Severity Calculator show when a problem is worth raising with a doctor, but only a clinician can diagnose a sleep disorder.
Medical information boundary. These calculators are for general education and planning. They are not medical advice, a diagnosis or a substitute for a doctor. See a doctor about loud snoring with pauses in breathing, falling asleep during the day, or sleep problems that last more than a few weeks.