This live calculator reads the current time on your device and instantly calculates every cycle-aligned wake-up time available if you fell asleep right now. No manual entry needed — select your sleep onset speed below and your personalised wake times update automatically every minute.
⚙️ How fast do you usually fall asleep?
Your Cycle-Aligned Wake Times
Why Cycle-Aligned Wake Times Feel Different
Waking at a cycle boundary means your brain is in light sleep (N1/N2) rather than deep sleep (N3). You surface naturally instead of being dragged out mid-cycle.
Every adult sleep cycle takes approximately 90 minutes. Your brain completes N1 → N2 → N3 → REM in each cycle. Waking between cycles — not within one — is the key insight.
REM sleep peaks in later cycles. More complete cycles = more REM = better mood, memory, and emotional regulation the next day. Always prioritise 5 cycles (7.5 hrs).
The 14-minute default is a population average. If you fall asleep in 5 minutes, your cycles shift accordingly. Use the selector above to adjust for your personal pattern.
Frequently Asked Questions
Methodology & Sources
Wake times are calculated by adding 90-minute cycle intervals to the current device time, plus selected onset latency. The 14-minute default onset is the population mean from American Academy of Sleep Medicine polysomnography data. Results update every 60 seconds. All calculations run client-side — no data is sent to any server. Time is read from the browser's local clock (device timezone).