Hespera - Sleep Calculator

100% free. One minute about your day — Hespera plans your bedtime, wake-up window, sleep cycles and tomorrow's energy. No wearable, no subscription.

Hespera helps you sleep smarter by turning the day you actually lived into a clear plan for tonight. Caffeine, stress, naps, exercise, screen time, alcohol, and the way you felt this morning can all affect your sleep. Hespera brings those signals together so you can make better decisions before bedtime — without turning sleep into another chore.

PLAN YOUR NIGHT

• Get a personalized bedtime target
• See your recommended wake-up window
• Know when to start winding down
• Adjust your plan around the day you actually had

TRACK CAFFEINE

• Log coffee, tea, and energy drinks
• See how much caffeine may still be in your system near bedtime
• Find a better caffeine cutoff for your schedule
• Understand how late caffeine may affect your night

KEEP YOUR SLEEP HISTORY ACCURATE

• Confirm how your night actually went
• Correct bedtime and wake-up time when needed
• Skip nights you do not want to count
• Keep incomplete data from turning into misleading insights

UNDERSTAND YOUR SLEEP DEBT

• See how short nights add up across the week
• Understand how recent sleep compares with your needs
• See why one late night can affect more than one morning
• Follow your recovery over time

READ YOUR ENERGY

• See when you may feel more alert
• Identify likely low-energy periods
• Understand how tonight may affect tomorrow
• Use your sleep history to plan your day more intelligently

DISCOVER REAL PATTERNS

• See which habits repeatedly appear alongside better or worse sleep
• Compare caffeine, stress, exercise, naps, alcohol, and screen time
• Avoid conclusions based on one unusual night
• Get insights only when there is enough data to make them meaningful

REVIEW YOUR NIGHTS

• Browse your sleep history
• Open and inspect individual nights
• Correct previous entries
• Keep a clean record of how your sleep changes over time You do not need a perfect routine, a complicated sleep journal, or another list of generic tips. Just tell Hespera what happened today and use that information to make tonight better.

Hespera is not a medical device and is not intended to diagnose, treat, cure, or prevent any medical condition or sleep disorder. If you experience serious or persistent sleep problems, consult a qualified healthcare professional.