Sleep Calculator
Find your optimal bedtime based on sleep cycles and improve your sleep quality with scientifically-backed recommendations.
Sleep Time Calculator
Sleep Cycle Visualization
A typical adult goes through 4-6 sleep cycles per night, each lasting about 90 minutes. Waking up at the end of a cycle helps you feel more refreshed.
Recommended Sleep Duration by Age
| Age Group | Recommended Hours | Notes |
|---|---|---|
| Infants (1-2 years) | 11-14 hours | Including naps |
| Preschool (3-5 years) | 10-13 hours | Including naps |
| School Age (6-13 years) | 9-11 hours | Consistent bedtime important |
| Teens (14-17 years) | 8-10 hours | Biological clock shifts later |
| Adults (18-64 years) | 7-9 hours | Individual needs may vary |
| Seniors (65+ years) | 7-8 hours | May have lighter, fragmented sleep |
Source: National Sleep Foundation recommendations
Understanding Sleep Stages
Stage 1: Light Sleep
The transition between wakefulness and sleep. Muscle activity slows down and you may experience sudden muscle contractions. Easily awakened during this stage.
Stage 2: Light Sleep
Body temperature drops and heart rate slows. Brain waves show bursts of activity called sleep spindles, which help with memory consolidation.
Stages 3-4: Deep Sleep
Also known as slow-wave sleep. This is when your body repairs tissues, builds bone and muscle, and strengthens the immune system. Most difficult to wake up from.
REM Sleep
Rapid Eye Movement sleep is when most dreaming occurs. Brain activity increases, heart rate and breathing become irregular. Important for emotional processing and memory consolidation.
Sleep Hygiene Tips
- Consistent Schedule: Go to bed and wake up at the same time daily, even on weekends.
- Bedroom Environment: Keep your bedroom dark, quiet, and at a comfortable temperature (65-68°F/18-20°C).
- Limit Screen Time: Avoid electronic devices 1 hour before bed due to blue light affecting melatonin production.
- Watch Diet: Avoid large meals, caffeine, and alcohol close to bedtime.
- Regular Exercise: Physical activity promotes better sleep, but avoid exercising close to bedtime.
- Manage Stress: Try relaxation techniques like deep breathing, meditation, or gentle stretching before bed.
- Limit Naps: Short naps (20-30 minutes) are beneficial, but avoid long or late-day naps.
- Comfortable Bedding: Invest in a comfortable mattress and pillows suitable for your sleeping position.
Circadian Rhythms and Sleep
Your body's circadian rhythm is a natural, internal process that regulates the sleep-wake cycle and repeats roughly every 24 hours. It's controlled by a part of your brain called the suprachiasmatic nucleus (SCN).
Light is the primary factor that influences your circadian rhythm. When light enters your eyes, it signals to your brain that it's time to be awake. As darkness falls, your body produces melatonin, a hormone that promotes sleep.
Factors that can disrupt your circadian rhythm:
- Jet lag from traveling across multiple time zones
- Shift work that requires staying awake at night
- Irregular sleep schedules
- Excessive exposure to blue light from screens at night
- Aging, which can alter sleep patterns
Tips for Maintaining Healthy Circadian Rhythms:
- Morning Light Exposure: Get 15-30 minutes of sunlight in the morning to help set your internal clock.
- Dimming Lights: Reduce light exposure in the evening, especially blue light from electronic devices.
- Consistent Mealtimes: Eating at regular times helps reinforce your body's circadian rhythm.
- Regular Exercise: Physical activity can help regulate your sleep-wake cycle when done consistently.
- Limit Caffeine: Avoid caffeine after mid-afternoon as it can stay in your system for 6+ hours.
Did You Know?
Your body temperature, hormone levels, and even digestive activity follow circadian patterns. This is why eating late at night can disrupt sleep and metabolism.