# SleepCycle: Sleep Calculator — Science-Based Sleep Optimizer > Science-based sleep cycle calculator for optimal waking and sleeping times. (iPhone/iPad app by MARTHEN LUKAS LUMINGKEWAS.) - Source: https://appshunter.io/ios/app/sleepcycle-sleep-calculator/id6763971847 (this page in markdown: same URL + `.md`) - Developer: [MARTHEN LUKAS LUMINGKEWAS](https://appshunter.io/developer/1895580837) - Category: Lifestyle, Productivity - Price: Free with in-app purchases - Rating: 5.00/5 from 1 App Store ratings - Age rating: 12+ - Requires: iOS 18.0 · 8 MB - Languages: American English - Released: 2026-05-18 - Data updated: 2026-06-29 - Monetization: free with in-app purchases - User reviews in markdown: https://appshunter.io/ios/app/sleepcycle-sleep-calculator/id6763971847/reviews.md ## What is SleepCycle? SleepCycle Calculator helps you find the ideal time to go to sleep or wake up — based on real sleep science. Built around the 90-minute sleep cycle model, the app calculates optimal bedtimes and wake-up windows so you always rise at the lightest stage of sleep, feeling alert and refreshed. WHETHER YOU SET A WAKE TIME OR SLEEP NOW • Wake-Up Mode: Enter your desired wake-up time and the app calculates 4–6 ideal bedtimes working backwards in 90-minute cycles, plus a 14-minute fall-asleep buffer. • Sleep Now Mode: Tap "Sleep Now" and the app instantly calculates your best wake-up times based on the current time. BUILT-IN SMART ALARM • Tap any suggested time to set it as your alarm instantly. • Choose from 6 soothing alarm sounds: Gentle Bells, Forest Birds, Ocean Waves, Digital Beep, Soft Chime, and Cosmic Hum. • Preview sounds before selecting. • Dismiss or snooze (9 minutes) when the alarm fires. • Push notifications ensure your alarm fires even when the app is in the background. SLEEP HISTORY & TRACKING • Every dismissed alarm automatically logs a sleep session — bedtime, wake time, duration, cycle count, and quality rating. • View your sleep history on an interactive calendar with color-coded indicators. • Track 7-day and 30-day sleep averages, your best night, and total nights logged. • Weekly bar chart shows sleep duration at a glance. SLEEP SCIENCE EDUCATION • Learn what a sleep cycle really is and why timing matters. • Explore the 4 sleep stages (N1, N2, N3, REM) with durations and biological functions. • Understand the 90-minute rule and the 14-minute sleep onset latency formula used by this app. • Science-backed sleep tips on room temperature, blue light, caffeine, and more. • 7 tappable references to peer-reviewed sources including the Sleep Foundation, NIH, and Harvard Health. BEAUTIFUL DESIGN • Deep indigo night-sky aesthetic inspired by Apple's bedtime design language. • Color-coded quality labels: Optimal, Great, Good, and Light for each sleep option. • Smooth animations, haptic feedback, and a breathing moon animation for a calming experience. SleepCycle Calculator is perfect for anyone who wants to stop waking up groggy and start waking up energized — backed by science, not guesswork. Note: A medical disclaimer is included in the app. This app is not intended to diagnose or treat sleep disorders. For serious sleep concerns, please consult a healthcare professional. PREMIUM ACCESS Try SleepCycle Pro free for 14 days. After the trial, unlock full lifetime access for a one-time purchase of $19.99 — no subscription, ever. Premium features include personalized sleep insights, full history tracking, and all future updates. ## Key features - Calculates optimal bedtimes and wake-up windows - Smart alarm with soothing sounds - Sleep history and tracking - Sleep science education - Personalized sleep insights (Premium) ## Pricing and in-app purchases Base price: Free. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | Lifetime Access | $19.99 | one-time | ## Frequently asked questions about SleepCycle ### What is the SleepCycle smart alarm? The smart alarm in SleepCycle is designed to wake you up during your lightest sleep stage within a 30-minute window before your set alarm time. This helps you feel more alert and less groggy upon waking. ### How does SleepCycle calculate optimal sleep times? SleepCycle is built around the 90-minute sleep cycle model. It calculates ideal bedtimes and wake-up windows by working backwards or forwards in these cycles, aiming to align with your lightest sleep phase. ### What are the premium features of SleepCycle? SleepCycle Pro offers premium features such as personalized sleep insights, full history tracking, and access to all future updates. A 14-day free trial is available, followed by a one-time purchase for lifetime access. ### Does SleepCycle have ads? No, SleepCycle does not contain advertisements. The app is free to download and use, with optional in-app purchases for premium features. ### What devices does SleepCycle support? Currently, SleepCycle is supported on iPhone devices. The app is designed to leverage the specific functionalities available on iOS. ### How often is SleepCycle updated? The latest version of SleepCycle is 1.0.8, which was last updated on May 19, 2026. Updates typically include bug fixes, performance improvements, and new features. ### What is the age rating for SleepCycle? SleepCycle has an age rating of 12+. This indicates that the content is generally suitable for users aged 12 and older. ### Can SleepCycle diagnose sleep disorders? No, SleepCycle includes a medical disclaimer stating it is not intended to diagnose or treat sleep disorders. For serious sleep concerns, users should consult a healthcare professional. ## Version history (last 1 release) ### 1.0.8 — 2026-05-19 No release notes. ## More apps by MARTHEN LUKAS LUMINGKEWAS - [Wedding Bloom Planner](https://appshunter.io/ios/app/wedding-bloom-planner/id6763984316) - [Generosity Tracker](https://appshunter.io/ios/app/generosity-tracker/id6764133511) - [Funeral Planning Checklist](https://appshunter.io/ios/app/funeral-planning-checklist/id6764155714) - [aedb-peak: Budget Tool](https://appshunter.io/ios/app/aedb-peak-budget-tool/id6764436209) - [GrowBook: Child Growth Tracker](https://appshunter.io/ios/app/growbook-child-growth-tracker/id6770141535) All apps by MARTHEN LUKAS LUMINGKEWAS: https://appshunter.io/developer/1895580837 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-29.*