Sleep Calculators and Guides
Everything on Vanta Calc about when to sleep and when to wake. The calculators and guides below use the same maths: 90-minute sleep cycles, plus the 14 minutes most people take to fall asleep, so the alarm lands at the end of a cycle rather than in the middle of one.
Sleep calculators
- Sleep Cycle Calculator
Find a bedtime or wake-up time from 90-minute sleep cycles, or work out how much you slept.
- Sleep Debt Calculator
Add up how many hours short of your sleep target the last week left you, and how many nights it takes to repay.
- Nap Calculator
Find the alarm time for a 20-minute power nap or a 90-minute full-cycle nap.
- Sleep Efficiency Calculator
Work out what share of your time in bed you spent asleep, with the 85% good-sleep reference level.
- US Daylight Saving Sleep Planner
Find the next US clock change and get a 3-night bedtime plan for spring forward or fall back.
- Caffeine and Bedtime Calculator
See how much caffeine from your drinks is left at bedtime, and when it falls to a level you choose, with an adjustable half-life.
- Jet Lag Calculator
Find the time difference between two cities on your travel dates and a night-by-night plan for shifting your body clock.
Bedtime guides by wake-up time
- Wake up at 4 AM
Bedtimes for a 4 AM alarm: the early-evening schedule that still fits whole sleep cycles.
- Wake up at 5 AM
Bedtimes for a 5 AM alarm, with the commuter, gym and early-shift schedules worked out.
- Wake up at 6 AM
Bedtimes for the most common alarm time, 6 AM, with school-run and workday schedules.
- Wake up at 7 AM
Bedtimes for a 7 AM alarm, including the late-night options that cross midnight.
Bedtimes at a glance
| Wake up at | 6 cycles (9 h) | 5 cycles (7.5 h) | 4 cycles (6 h) |
|---|---|---|---|
| 4 AM | 6:46 PM | 8:16 PM | 9:46 PM |
| 5 AM | 7:46 PM | 9:16 PM | 10:46 PM |
| 6 AM | 8:46 PM | 10:16 PM | 11:46 PM |
| 7 AM | 9:46 PM | 11:16 PM | 12:46 AM |
Assumes 14 minutes to fall asleep. Other times: use the sleep cycle calculator above.
How much sleep do you need?
| Group | Age | Recommended sleep per 24 hours |
|---|---|---|
| Newborn | 0-3 months | 14-17 hours |
| Infant | 4-12 months | 12-16 hours (including naps) |
| Toddler | 1-2 years | 11-14 hours (including naps) |
| Preschool | 3-5 years | 10-13 hours (including naps) |
| School age | 6-12 years | 9-12 hours |
| Teen | 13-17 years | 8-10 hours |
| Adult | 18-60 years | 7 or more hours |
| Adult | 61-64 years | 7-9 hours |
| Adult | 65 years and over | 7-8 hours |
Source: CDC: About Sleep (how much sleep you need), U.S. Centers for Disease Control and Prevention. These are planning guides, not medical advice.