Enter your wake-up time. Instantly see if you'll get enough sleep tonight.
| Sleep rating | — |
| vs. recommended minimum | — |
| Deep sleep window | — |
No apps. No accounts. Just answers.
"Can I sleep now?" "How long should I nap?"
One or two inputs. Bedtime, wake-up time, nap length — that's it.
Duration, cycles, rating, and a short tip.
Pick the one that fits your question.
Enter bedtime and wake time. Get actual sleep length, cycle count, and a data-backed rating.
Most UsedHow long until you wake up? See cycles at a glance.
Reverse-engineer your ideal bedtime from 90-min cycles.
PopularPick a nap length and see the best wake time.
Recommended daily sleep by age.
Crossing time zones? Estimate adjustment days.
Track deficit from consecutive short nights.
When your last coffee clears your system.
Evidence-based guides, tool walkthroughs, and the science behind better rest.
Eight hours in bed does not always mean eight hours of sleep. Learn why you still wake up tired and how to fix it.
Coffee's kick lasts longer than most people think. Here's a realistic timeline, plus how to time your last cup so it doesn't wreck your sleep.
Weekend sleep-ins feel great, but can you really repay a sleep debt in two days? Here is what the research says and how to recover smarter.
Jet lag usually lasts one day for every time zone you cross. Here is how to shorten it using light, timing, and a few sleep tools.
Most 1 year olds need 11 to 14 hours of sleep per day, including naps. Here is how to tell if your toddler is getting enough.
A 10 to 20 minute nap can sharpen your focus, but a 90 minute nap helps with creativity. Learn the best nap length for your goal.