Real Sleep Calculator

Nap calculator

Wake refreshed from your nap — not groggy

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Find your ideal nap wake time

A nap calculator helps you avoid the dreaded post-nap grogginess. Whether you need a quick power nap calculator result for 20 minutes or a full 90-minute cycle, timing your wake-up matters as much as the nap length itself.

For a power nap, set your current time and we add 20 minutes plus 5 minutes buffer for falling asleep. For a full cycle nap, we add 90 minutes plus latency — giving you one complete sleep cycle and a more restorative rest.

Looking for nighttime sleep timing? Try our sleep cycle calculator or bedtime calculator.

The right sleep mask makes power naps 10x easier. We like the Manta Sleep Mask for its zero eye pressure design.

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Frequently asked questions

How long should a power nap be? +

A power nap should be 20 minutes or less. This keeps you in light sleep and avoids sleep inertia from entering deeper stages.

Is a 20 minute nap good? +

Yes. A 20-minute nap boosts alertness, mood, and cognitive performance without the grogginess of longer naps.

What is a caffeine nap? +

A caffeine nap combines a 20-minute nap with coffee consumed right before lying down. Caffeine kicks in as you wake, doubling the alertness boost.

Why do I feel worse after a nap? +

Napping longer than 30 minutes often pushes you into deep sleep. Waking from deep sleep causes sleep inertia — that heavy, disoriented feeling.

What is the best time of day to nap? +

The ideal nap window is early afternoon (1–3 PM) when your circadian rhythm naturally dips. Napping after 4 PM can interfere with nighttime sleep.

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