Calculadora de Sono Online Grátis
Calculate ideal bedtimes and wake times based on 90-min REM sleep cycles
Sleep quality is determined not just by duration, but by when you wake up within your sleep cycle. Waking mid-cycle — when you're in deep sleep or REM — causes the grogginess known as sleep inertia. This calculator identifies optimal bedtimes and wake times aligned to complete 90-minute sleep cycles, so you wake at the lightest sleep stage feeling refreshed.
Frequently Asked Questions
Sobre Esta Calculadora
Sleep cycles last approximately 90 minutes each and consist of four stages: three non-REM stages (light sleep, deeper sleep, and deep restorative sleep) followed by REM sleep. A full night's sleep for adults cycles through this pattern 5–6 times. The proportion of deep sleep is highest in the first half of the night; REM sleep dominates in the second half.
Waking during deep sleep triggers sleep inertia — the groggy, disoriented feeling that can persist for 30–60 minutes. Timing your alarm to the end of a complete cycle, when you're in the lightest sleep stage, allows you to wake feeling naturally alert. The 14-minute sleep onset estimate is based on average sleep latency data, though individuals vary widely.
Chronotype — whether you're naturally a morning or evening person — is partly genetic. Forcing a chronotype to dramatically different sleep times can disrupt circadian rhythms. The most effective sleep improvements usually combine consistent wake times (even on weekends) with light exposure management in the morning.
Acorde sentindo-se revigorado calculando seus ciclos de sono.
Fórmula
Optimal Wake = Bedtime + (90min × N cycles) + 14min sleep onset Recommended: 5–6 cycles (7.5–9 hours)
Exemplo Resolvido
Finding the best bedtime to wake up at 6:30 AM
Entradas:
- Target wake time: 6:30 AM
- Average sleep onset time: 14 minutes
Passo a Passo:
- Working backwards from 6:30 AM in 90-minute increments + 14 min onset:
- 6 cycles (9 hours): Bedtime = 6:30 AM − 9 hrs − 14 min = 9:16 PM
- 5 cycles (7.5 hours): Bedtime = 6:30 AM − 7.5 hrs − 14 min = 10:46 PM
- 4 cycles (6 hours): Bedtime = 6:30 AM − 6 hrs − 14 min = 12:16 AM
- Recommended options: 9:16 PM (ideal) or 10:46 PM (practical for most adults)
Dicas
- Each sleep cycle is ~90 minutes. Waking mid-cycle causes grogginess.
- Adults need 7–9 hours (5–6 cycles). Teens need 8–10 hours.