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Nap optimizer
Uses homeostatic sleep pressure (time awake) and distance to bedtime to judge whether a nap helps or undermines night sleep. End power naps ≥ 5 h before bed; full-cycle naps ≥7 h before.
Awake ~7.5 hBed in ~8.0 h
Nap advisable — likely OK
Moderate homeostatic pressure with enough evening runway — a short nap is usually compatible with tonight’s sleep if it ends well before the cutoff.
Duration
Prefer 10–20 minutes; avoid slow-wave sleep if you hate sleep inertia.
10–20 min (alertness)
End by 17:30 · start by ~17:10 for a full 20 min
~90 min (full cycle)
End by 15:30 · start by ~14:00
Educational estimates only. Sleep and caffeine metabolism vary widely. This is not medical advice; talk to a clinician if you have insomnia, apnea, or other conditions.