Best sleep tracker tools: wake up refreshed, not groggy
Free sleep calculator and sleep diary, plus honest guides to the best sleep tracker for you. Tell us when you need to be up and we'll show the best bedtimes in 90-minute sleep cycles.
To wake up at 7:00 AM, try falling asleep at
Best match
11:15 PM
5 cycles Β· 7h 30m of sleep
Other options
- 9:45 PM Ideal 6 cycles Β· 9h of sleep
- 12:45 AM Okay 4 cycles Β· 6h of sleep
Why: each cycle is about 90 minutes and we allow 15 minutes to fall asleep, so the alarm lands between cycles. Aim for 5β6 cycles (7.5β9 hours) if you can.
Tonight
All tools
Sleep tools for every age
Pick your world. Every tool has a short guide that explains the why.
- Wake-up Going to bed now? See the best times for your alarm. Guide β
- Nap Wake-up times for a 20, 30, 60 or 90-minute nap. Guide β
- Power nap Tell us how much time you have; get the best nap and a timer. Guide β
- Sleep debt Add up the last 7 nights and plan a realistic recovery. Guide β
- Caffeine The latest time for your last coffee, tea or energy drink. Guide β
- Sleep needs How many hours of sleep from newborn to older adult. Guide β
- Chronotype quiz Are you a lark, bear, fox or owl? Find your natural rhythm. Guide β
- Sleep quality check Ten quick questions and tips for the areas that matter most. Guide β
- My sleep Your saved settings, diary averages and plans in one place.
- Sleep diary Log bedtime and wake-up; see a 7-day chart and averages. Guide β
- Routine chart Build and print an illustrated routine with your childβs name. Guide β
- Reward chart A printable sticker chart for a week of great bedtimes. Guide β
- Countdown A full-screen moon that fills as bedtime gets closer. Guide β
- Sleeps until Count the sleeps until a birthday, holiday or trip. Guide β
- Night light A dim, warm, animated screen with an auto-off timer. Guide β
- Bedtime stories Short, calm read-aloud stories for small sleepers. Guide β
Why use this one
Small tool, built for every night
Wake at, bed at, or sleep now
Three ways to count in sleep cycles, so it works for tonight whatever your plan is.
Tuned to you
Change how long you take to fall asleep and how long your cycles run.
Daily reminder
Download a calendar reminder for your bedtime. No account, no sign-up.
Remembers you
Your last settings are saved in this browser, so tomorrow night is one tap.
Easy on tired eyes
Dark by default in the evening, with a light mode and a 12/24-hour clock switch.
Guides
Learn the why behind the tools
- Adult sleep Caffeine and sleep: when to have your last cup How caffeine can affect sleep hours after you drink it, and how to choose a sensible cutoff time.
- Adult sleep How long should a nap be? 10, 20, 30 or 90 minutes What each nap length does, and how to choose one that fits your day without hurting your night.
- Adult sleep Sleep cycles explained (and how accurate the 90-minute rule is) What happens during a night of sleep, what a cycle is, and why 90 minutes is an average rather than a rule.
- Baby and toddler sleep Baby wake windows by age: what the ranges really mean How long babies are usually comfortable awake between sleeps, why the numbers vary so much, and how to use them gently.
- Kidsβ sleep How much sleep does my child need? Recommended hours of sleep for babies, toddlers, school-age children and teens, and how to turn them into a bedtime.
- Sleep myths Myth: you can catch up on sleep at the weekend What research shows about weekend recovery sleep, and what to do instead.
FAQ
Questions about sleep cycles
How does the sleep calculator work?
Sleep moves in cycles of roughly 90 minutes. We count backwards from your wake-up time in whole cycles and add the time it takes you to fall asleep, so your alarm lands at the end of a cycle, when sleep is lightest.
How many sleep cycles do I need?
Most adults feel best after 5β6 cycles, which is 7.5β9 hours. Four cycles (6 hours) is a bare minimum you should not rely on every night.
Why does it add 15 minutes?
The average person takes around 15 minutes to fall asleep. Open "Fine-tune for you" to change this if you drop off faster or slower.
Is a 90-minute cycle accurate for everyone?
It is an average. Real cycles range from about 80 to 110 minutes and change through the night, so treat the results as a good starting point and adjust the cycle length to what works for you.
Does this replace medical advice?
No. If you regularly feel unrested, snore heavily or struggle to sleep, speak to a doctor.
Read more about how sleep cycles work β Β· More sleep tracker questions β
The best sleep tracker toolkit: free tools, honest guides
Looking for the best sleep tracker? You are in the right place, with a twist. Best Sleep Trackers is two things in one: a set of free sleep tools that run in your browser, and a set of plain-English guides to the devices and apps that track sleep. The tools include a sleep calculator that works out when to go to bed, a nap calculator, a free online sleep diary and planners for babies, kids, teens, shift workers and travellers. The guides help you choose between an Apple Watch, a smart ring, a phone app or no device at all.
Most people do not need the most expensive tracker. They need to sleep at consistent times, get enough hours and understand their own pattern. Everything on this site is built around that idea.
Start with the best sleep tracker guide
Our best sleep tracker guide for 2026 explains the main types of device and which one suits an iPhone user, an Android user, someone who wants recovery data and someone who hates wearing anything in bed. It also shows what sleep trackers do well, which is measuring total sleep and timing, and what they do less well, which is separating sleep stages. If you own an iPhone, jump to the Apple Watch sleep tracker guide for setup steps and a clear explanation of sleep stages, sleep score and apnea notifications.
Free sleep tracker apps and sleep tracker apps that actually work
Many free sleep tracker apps are free to download and limited until you pay. We explain how to spot the difference, what to check about privacy and which built-in options cost nothing. Our guide to sleep tracker apps that actually work covers how apps measure sleep and which approach improves it, including CBT-I programmes for insomnia. If you want an alarm that wakes you in light sleep, read about the sleep cycle app approach and its free calculator alternative.
Best sleep tracker without a subscription
Monthly fees add up quickly. Our page on the best sleep tracker without a subscription shows which watches and rings keep core sleep data free, which devices need a membership and how to compare the real cost over three years. If you would rather spend nothing, the sleep diary is a genuine free sleep tracker that needs no app.
An online sleep monitor that stays private
The online sleep monitor built from our sleep diary and My sleep dashboard records your bedtime, wake-up time and how rested you feel, then shows a seven-day chart, your averages and how much your bedtime varies. Everything stays in your browser. There is no account to create and no data to sell.
How the sleep calculator works
The calculator at the top of this page answers a simple question: what time should I go to bed? It counts back from your wake-up time in 90-minute sleep cycles, adds the time you take to fall asleep and shows the bedtimes that let you wake at the end of a cycle. You can also start from your bedtime and see the best alarm times, or choose "sleep now". The idea is the same one that sleep cycle apps use for their smart alarms, applied in advance so that it needs no microphone or sensors.
Cycles vary between people and through the night, and 90 minutes is an average, so use the fine-tune options and trust how you feel. For the science, read how sleep cycles work.
Tools for every age and situation
Adults can use the bedtime calculator, wake-up calculator, nap calculator, sleep debt calculator and caffeine cutoff calculator. To fall asleep, try sleep sounds, a guided breathing exercise or a body scan. Parents have the baby wake window calculator, a baby nap schedule, a kids bedtime calculator and printable routine and reward charts. Teenagers get the school-night bedtime tool and the exam week planner. Special situations are covered by the shift work planner, jet lag planner and new parent night planner.
What a sleep tracker can and cannot tell you
A good tracker tells you when you slept and how regular you are. It cannot read your mind or diagnose a disorder, and its sleep stages and scores are estimates. Watch the trend, ignore the nightly swings and pay attention to how you feel in the daytime. If you snore loudly, stop breathing in your sleep, struggle to fall asleep most nights or feel sleepy while driving, speak to a doctor. Our tools provide general information and are not medical advice.
Why start with free tools before buying a tracker?
Many people buy a device hoping it will fix their sleep, then find the numbers only confirm what they suspected: they go to bed late and sleep too little. Free tools help you act on that straight away. Pick a wake-up time with the wake-up calculator, set a bedtime with the bedtime calculator and keep a sleep diary for two weeks. If you still want more data after that, you will know what to look for in a tracker.
How we keep this site honest
The tools run in your browser and store settings on your device. We do not sell data, we show no tracker-style scores that we cannot justify and we cite sources for health claims on our guide pages. We are not a medical service, and nothing here replaces advice from a doctor. See our about page and privacy page for more.
Frequently asked questions
What is the best sleep tracker?
It depends on your phone, budget and goal. iPhone owners often choose the Apple Watch, Android users have Pixel, Galaxy and Garmin options, and a smart ring suits people who dislike wearing a watch in bed. See the best sleep tracker guide for a full comparison.
Is there a free sleep tracker?
Yes. Your phone's built-in sleep features, the free tiers of sleep apps and a free online sleep diary all cost nothing. Check which features sit behind a paywall.
What is the best sleep tracker without a subscription?
Apple Watch and Garmin watches are widely noted for core sleep tracking with no required membership, and Fitbit, Samsung and Withings keep core data free. Verify current terms before buying.
Do sleep tracker apps really work?
They are reasonably good at bedtime, wake-up time and total sleep and less accurate for sleep stages. They help most when you act on the patterns they show.
How does a sleep cycle calculator work?
It counts back from your wake-up time in whole 90-minute cycles and adds the time you take to fall asleep, so you wake near the end of a cycle.
General information only. This tool gives general sleep information and is not a substitute for medical advice. If you're worried about your sleep or your child's, talk to a doctor or pediatrician.