Why do I feel worse after a 30-minute nap?
You likely woke during deep sleep (Stage 3), causing sleep inertia. Stick to 10-20 or 90 minutes.
Health Fitness
Power Nap Calculator
Estimate power nap with quick inputs.
Fast, practical estimates
Adjust inputs for the most useful result.
What this calculator does
A power nap calculator determines optimal nap duration and timing. Short naps (10-20 minutes) boost alertness without sleep inertia. Longer naps (60-90 minutes) allow deep sleep and REM but may cause grogginess upon waking.
How it works
Select desired benefit. Calculator recommends nap duration and ideal timing (typically 1-3 PM based on circadian rhythm).
Formula
Power nap: 10-20 min (Stage 2 sleep). Full cycle: 90 min (includes deep + REM). Avoid 30-60 min (wake during deep sleep).
Tips for using this calculator
- 10-20 minutes is optimal for alertness boost
- Avoid naps after 3 PM—may disrupt nighttime sleep
- Dark, quiet environment improves nap quality
- Set alarm to avoid oversleeping into deep sleep
- Caffeine nap: coffee before 20-min nap maximizes alertness
Frequently asked questions
What's the best time to nap?
1-3 PM aligns with natural circadian dip. Avoid napping after 3 PM.
Can naps replace nighttime sleep?
No, naps supplement but don't replace full night's sleep. Most adults need 7-9 hours nightly.