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Nap Calculator

Find the perfect nap length and wake-up time. A power nap energizes — the wrong length leaves you groggy for an hour.

Choose your nap length

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Power Nap

20 min

✦ Best choice

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Deep Nap

60 min

⚠ Risky

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Full Cycle

90 min

◆ Restorative

Includes ~14 min to fall asleep

Set your alarm for

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The science of napping

Nap length determines which sleep stage you wake from — and that decides whether you feel sharp or groggy.

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20 min — Power nap

Stays in light sleep (N1–N2). Boosts alertness, mood and reaction time. Wake up sharp — no grogginess.

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60 min — Avoid this

Lands in deep sleep (N3). Waking here causes sleep inertia — 30–60 min of grogginess. Skip this length.

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90 min — Full cycle

Completes one full cycle including REM. Wake at the lightest stage feeling genuinely restored.

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Best time: 1–3 PM

Natural post-lunch circadian dip. Napping after 3 PM can push back your bedtime.

Common questions

How long should a nap be?

Either 20 minutes (power nap, stays in light sleep) or 90 minutes (full cycle with REM). Avoid 30–60 min naps — you wake mid-deep-sleep and feel groggy for up to an hour.

Why do I feel worse after a long nap?

This is sleep inertia. A 45–60 minute nap puts you into N3 deep sleep. Waking from deep sleep leaves your brain in a low-activity state for 15–60 minutes. Keep naps to 20 min or extend to a full 90.

What is a coffee nap?

Drink a coffee then immediately take a 20-minute nap. Caffeine takes ~20 min to kick in, so it hits just as you wake — combining the nap's restorative effect with caffeine's alertness boost. Research shows this outperforms either alone.

Best nap length by situation

Searches like “20 minute nap vs 90 minute nap,” “why do naps make me groggy,” and “best nap time after lunch” all come down to sleep stage timing. Short naps protect alertness; full-cycle naps protect recovery.

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20-minute power nap

Best for quick alertness before studying, driving, or afternoon work. It usually ends before deep sleep, so sleep inertia is lower.

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90-minute full-cycle nap

Best when you are sleep deprived or need deeper recovery. A full cycle can include REM and usually feels smoother than waking at 45-60 minutes.

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Coffee nap timing

Drink coffee, start a 20-minute nap, and caffeine begins working around wake-up. Avoid this late in the day if bedtime is within 8-10 hours.

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Best time to nap

Most people nap best in the early afternoon, roughly 1-3 PM. Later naps can reduce sleep pressure and make nighttime sleep harder.