Free sleep tools and calculators
Work out a bedtime, your sleep debt or sleep efficiency, time your caffeine, size a CPAP battery, and understand screening scores. Every tool shows its math and its limits.
Sleep schedule
Bedtime CalculatorPick the time you need to wake up and see bedtimes that allow 6, 5 or 4 full sleep cycles of about 90 minutes, plus time to fall asleep.Wake-Up Time CalculatorEnter when you are going to bed and get wake-up times at the end of 4, 5 or 6 sleep cycles of about 90 minutes each.Nap Timing CalculatorEstimate a good early afternoon nap window from your wake-up time, and when to set the alarm for a short or full cycle nap.Jet Lag Recovery CalculatorEstimate roughly how many days your body clock needs to adjust after crossing time zones, and why flying east usually takes longer.Shift Work Sleep PlannerEnter when your shift ends, your commute and how long you need to sleep to get a suggested main sleep window after a night or late shift.
Screening scores
STOP-Bang Sleep Apnea ScreenerAnswer eight yes or no questions about snoring, tiredness, observed breathing pauses, blood pressure, BMI, age, neck size and sex to estimate obstructive sleep apnea risk.Epworth Sleepiness Score InterpreterAlready have an Epworth Sleepiness Scale total from 0 to 24? Enter it to see which daytime sleepiness band it falls in.Insomnia Severity Index Score InterpreterEnter an Insomnia Severity Index total from 0 to 28 to see whether it falls in the no insomnia, subthreshold, moderate or severe band.BMI Calculator for Sleep Apnea RiskCalculate body mass index in metric or US units and see the CDC weight category and whether it meets the STOP-Bang BMI over 35 item.
CPAP tools
AHI CalculatorCalculate the apnea hypopnea index from the number of apneas, hypopneas and hours of sleep, and see the adult or child severity band.CPAP Pressure Unit ConverterConvert a CPAP pressure in cm H2O to hPa, mbar, kPa, mmHg and psi, or convert a pressure in hPa or mbar back to cm H2O.CPAP Compliance CalculatorCheck whether your CPAP use meets the Medicare adherence rule of 4 or more hours on at least 70 percent of nights in a 30 day period.CPAP Battery Runtime CalculatorEstimate how many hours a battery will run your CPAP from its watt-hour rating, your machine's average power draw and conversion losses.CPAP Supply Replacement CheckerPick a CPAP part and enter how many days you have used it to see the usual Medicare replacement interval and how many days are left.
Habits
How Much Sleep Do I Need by AgeChoose an age group to see the recommended hours of sleep from the CDC, based on AASM consensus statements.Sleep Debt CalculatorCompare your weekly sleep against your sleep need to estimate how many hours of sleep debt you build up each week.Sleep Efficiency CalculatorWork out what percentage of your time in bed you actually spend asleep, the measure used in sleep diaries and CBT-I.Caffeine at Bedtime CalculatorEstimate how much caffeine is still in your body at bedtime from a drink earlier in the day, using an adjustable half-life.Social Jet Lag CalculatorCompare the midpoint of your sleep on workdays and free days to measure social jet lag, the weekly time zone shift from sleeping in on weekends.
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