# Sleep Cycle Calculator Refresh

> Calculates optimal sleep and wake times based on human sleep cycles. (iPhone/iPad app by DutchVirtual.)

- Source: https://appshunter.io/ios/app/sleep-cycle-calculator-refresh/id606923406 (this page in markdown: same URL + `.md`)
- Developer: [DutchVirtual](https://appshunter.io/developer/327914496)
- Category: Health & Fitness, Utilities
- Price: Free with in-app purchases
- Rating: 2.90/5 from 15 App Store ratings · 50 written reviews indexed
- Age rating: 4+
- Requires: iOS 11.1 · 77 MB
- Languages: American English, Dutch
- Released: 2013-03-13
- Data updated: 2026-06-10
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/sleep-cycle-calculator-refresh/id606923406/reviews.md

## What is Sleep Cycle Calculator Refresh?

Customer praise:
"It's so handy to think in terms of sleep cycles rather than hours" -- A.T.
"Getting the right amount of sleep has improved my health" -- D.S.
"...very attractive. It is very simple and the updates you have made to it over time have made it better." -- M.S.

Ever wonder why you sometimes wake up groggy, even if you have more sleep?

The reason: you've woken up in between your sleep cycles.

We all have multiple sleep cycles a night, and waking up during one will leave you feeling groggy and tired. Waking up between two separate ones, however leaves you waking up feeling refreshed, even if you've had less hours of total sleep.


* Counts in sleep cycles to calculate:
- Time to sleep, based on desired wake time
- Time to wake, based on desired sleep time

* This version includes:
- Age group optimization 
- Customize how long it takes to fall asleep
- Able to set an alarm, via in-app purchase
- Multiple themes to make it easy on the eyes
- Multiple wake-up sounds


DESCRIPTION:

By counting in sleep cycles and incorporating how long it takes for you to fall asleep, this Sleep Cycle determines when you should sleep and when you should wake up based on the average human sleep cycle. Humans naturally have multiple sleep cycles every night and it's during these sleep cycles that we are truly resting. 

If we wake up in the middle of one of these cycles, we will feel groggy and much more tired than normal because we have interrupted an important process. However, if we we wake up in between two sleep cycles, we will feel far more refreshed even if we've had less sleep. This is because humans naturally wake up in between sleep cycles, provided we aren't disturbed by things like alarm clocks and other loud noises.

## Key features

- Calculate sleep time based on desired wake time
- Calculate wake time based on desired sleep time
- Age group optimization
- Customize time to fall asleep
- Multiple themes
- Multiple wake-up sounds

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Alarm | $0.99 | one-time |
| Reminders | $0.99 | one-time |


## Recent user reviews (10 of 50)

All indexed reviews: https://appshunter.io/ios/app/sleep-cycle-calculator-refresh/id606923406/reviews.md

### 1/5 — Not for graveyard workers

*2017-12-01, version 3.2.8*

I was excited to use this app that could help me get on track of my sleeping schedule, especially working graveyard, but the settings wouldn’t let me make my bedtime at 7:30am. So there was no point on keeping this app.

### 5/5 — I love this App

*2017-08-26, version 3.2.7*

I never wake up grumpy when I use this App. Please fix the sound problem. This App is worth $5 - $25 when working properly.

### 1/5 — Terrible interface

*2017-03-24, version 3.2.7*

Completely unintuitive and a mess

### 5/5 — Love it

*2017-02-16, version 3.2.7*

The circular interface is unique and a lot easier to understand than other sleep cycle apps. I really like seeing the sleep cycles visually instead of a list of numbers and times. It works great for me and I wouldn't want to change anything about it.

### 5/5 — Unique, analog display interface

*2015-12-31, version 3.2.7*

It's like an analog watch vs. digital display, and can quickly at-a-glance see all the different wake times. 

When I usually use the app, I am half-asleep, so I don't need anything overly complicated to interpret, and don't want to have to input something then hit next to go to a different screen. I like how you can just rotate the dial to adjust, and the dial has graded colors showing times less than the recommended nine hours sleep as a darker color, and all the different times are right there on the same screen. 

This app is nice where everything is right there, which makes it simple and easy to use, in my opinion. 

I started using this after the 2014 update, and really like it. There are a ton of other apps if people want the same old thing, but this is has a really unique, easy on the eyes and aesthetically pleasing interface.

### 1/5 — Nope

*2015-12-18, version 3.2.7*

Just deleted this app as it is no longer of use to me. It doesn't calculate the times for me to go to bed or wake up... Just give me some clock thing that is of no use to me what so ever.... Bad choice there to "improve" what wasn't broken!!

### 1/5 — Old version was better

*2015-09-29, version 3.2.7*

I hate to be the "the old version before the update was better" guy, but the old version before the update was totally better. Now it has a circle thing which you have to rotate and it's just awful. It used to be that you could either enter your wake up time and it would give you your list of times, or you could choose "sleep now" and it would give you your wake-up times if you went to sleep within 15 minutes. Now, if you manage to work the awful circle thing, it just gives you one wake-up time. This app served me well for a long time. Sorry guys, you did the classic "fix it when it wasn't broken" scenario. Oh well, more free space on my phone.

### 1/5 — It was perfect until..

*2015-08-04, version 3.2.7*

This app was perfect until he "improved" it. Now, I rarely use it. It was simple and intuitive. Now it I'd difficult and combersome.

### 2/5 — Useful but a bug…

*2015-06-26, version 3.2.7*

When you use the app the first time the times are slightly different in color, so you could recommended sleep time. 

If switch from Adult to Child you lose that visual presentation.

### 2/5 — No Teens, I Guess...

*2015-02-26, version 3.2.3*

I switched the app to teenage setting, and now it simply refuses to open. Unusable at its current state. Looked visually apealling from what I saw though. Very clean and modernistic design, nice sleep delay features. 

Visuals: 5/5
Usability/Function: 1/5

## Frequently asked questions about Sleep Cycle Calculator Refresh

### What does this sleep cycle calculator do?

This app calculates your ideal sleep and wake times by considering natural human sleep cycles. It helps you understand why you might feel groggy even after a full night's sleep and suggests optimal times to go to bed and wake up to feel more refreshed.

### How does it calculate sleep and wake times?

The app counts in sleep cycles, which are natural periods of rest. It takes into account how long it typically takes you to fall asleep and your desired wake-up time to determine the best time to initiate sleep, and vice versa.

### Is there a cost to use this app?

The core functionality of the app is free. However, certain features, such as the ability to set an alarm, are available via in-app purchase.

### What are the benefits of using a sleep cycle calculator?

By waking up between sleep cycles rather than in the middle of one, you are more likely to feel refreshed and less groggy. This can lead to improved overall health and well-being, even if you have had fewer hours of sleep.

### Can I customize the app's appearance and sounds?

Yes, the app offers multiple themes to make it visually appealing and easier on the eyes. It also provides a selection of multiple wake-up sounds to choose from.

## Version history (last 5 releases)

### 3.2.8 — 2017-11-16

This app has been updated by Apple to display the Apple Watch app icon.

Support for iPhone X and Split View on iPads

### 3.2.7 — 2015-05-11

Fix for crash
Better support for iPhone 6/6 Plus

### 3.2.3 — 2014-11-25

Fixed a crash in the settings screen
Added the tutorial back

### 3.2.1 — 2014-11-03

Updated for iOS 8 and the new iPhone! The old interface has been replaced with a completely new draggable interface. We'll be adding some currently missing features in future releases, please stay tuned for more.

### 3.1.6 — 2014-09-03

Hidden forest theme now accessible to everyone. This may be the last update that's compatible with iOS 7. Should you want to be able to restore this version, please download it via iTunes on your PC.

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*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 2026-06-10.*